Annotated bibliography

Annotated Bibliography

Nolan Altman, James A. Brunberg, Allen D. Elster, Ajax E. George, David B. Hackney, Robert B. Lufkin, JeffreyS. Ross, Joel D. Swartz, Jane L. Weissman, and Samuel M. Wolpert

Brain Tumors and Cysts

Peterson DL, Sheridan PJ, Brown WE Jr. Animal models for brain tumors: historical perspectives and future direc-tions.

J

Neurosurg 1994;80:865-876.

An excellent review of animal models available for those involved in brain tumor research. Included are spontane-ous tumors, carcinogen-induced tumors, virus-induced tumors, models based on cell or tissue transplantation, and transgenic models. This paper is not for the general reader, but will be of great interest to academicians and researchers.OADE

Degenerative and Metabolic Disease and

Aging

Bensimon G, Lacomblez L, Meininger V, and the ALS/ Riluzole Study Group. A controlled trial of riluzole in amyotrophic lateral sclerosis. N Eng/ J Med 1994;330: 585-591.

One hypothesis about the origin of amyotrophic lateral sclerosis implicates abnormal accumulation of glutamate (the primary excitatory central nervous system neuro-transmitter) at synapses. Experimentally, riluzole inhibits the presynaptic release and postsynaptic actions of gluta-mate. This double-blind, placebo-controlled, prospective study was carefully performed and analyzed. Survival in the riluzole group was statistically greater than survival in the placebo group; the effect was greatest in patients with bulbar-onset amyotrophic lateral sclerosis, with only a "trend" in patients with limb-onset disease. Riluzole also slowed the deterioration of muscle strength. So far, ther -apy for amyotrophic lateral sclerosis has been inadequate. These results might constitute a breakthrough.OJLW Lipton SA, Rosenberg PA. Mechanisms of disease: exci-tatory amino acids as a final common pathway for neu-rologic disorders. N Eng/ J Med 1994;330:613-620.

This review article clarifies some mechanisms briefly alluded to in the preceding article. Glutamate, the principal excitatory CNS neurotransmitter, is involved in cognition, memory, movement, sensation. Overstimulation of gluta-mate receptors may cause "excitotoxicity" and cell death in acute injury (stroke, trauma, hypoglycemia, epilepsy) and chronic injury (amyotrophic lateral sclerosis). The article goes into exquisite technical detail, but it is impor-tant and worth skimming.OJLW

Aylward EH, Brandt J, Codori AM, Mangus RS, Barta PE, Harris GJ. Reduced basal ganglia volume associated with the gene for Huntington's disease in asymptomatic at-risk persons. Neurology 1994;44:823-828.

Volumes of the basal ganglia structures were signifi-cantly reduced in asymptomatic at-risk siblings of Hun-tington patients with marker-positive genes, but not in siblings with marker-negative genes.OSMW

SchneiderS, Feifel E, Ott D, Schumacher M, Luking CH, Deuschl G. Prolonged MRI T2 times of the lentiform nu-cleus in idiopathic spasmodic torticollis. Neurology 1994; 44:846-850.

Magnetic resonance (MR) findings in 22 patients with spasmodic torticollis were compared with those of 28 age-matched control subjects. T2 values in the putamen and pallidum on both sides were significantly higher in the patients than in the controls. The authors speculate that the findings could represent focal gliosis.OSMW

Rouanet F, Tison F, Dousset V, Corand V, Orgogozo JM. Clinical/scientific notes: early T2 hypointense signal ab-normality preceding clinical manifestations of central pontine myelinolysis. Neurology 1994;44:979-980.

In this interesting case report, the authors describe a patient with central pontine myelinolysis in whom an MR study revealed hypointense signal on T2-weighted se-quences in the basis pontis 1 week before the onset of clinical signs of the disease while the patient was still markedly hyponatremic. On a second MR image obtained 1 week later, the typical appearances of central pontine myelinolysis, hypointense areas on T1-weighted and hy-perintense on T2-weighted images, were seen.OSMW Graham SH, Meyerhoff DJ, Nat R, et al. Magnetic reso-nance spectroscopy of N-acetylaspartate in hypoxic-ischemic encephalopathy. Ann Neuro/1994;35:490-494.

Water-suppressed proton MR spectroscopic imaging measurements of N-acetylaspartate may be a sensitive way to measure selective neuronal loss of patients with hypoxic-ischemic encephalopathy as shown in this single case report.ONA

From Miami Children's Hospital (N.A.); University Hospital, Ann Arbor, Mich (J.A.B.); Bowman Gray School of Medicine, Winston-Salem, NC (A.D.E.); NYU Medical Center, New York (A.E.G.); Hospital of the University of Pennsylvania, Philadelphia (D.B.H.); UCLA School of Medicine, Los Angeles (R.B.L.); The Cleveland Clinic Foundation (J.S.R.); The Germantown Hospital and Medical Center, Philadelphia (J.D.S.); University of Pittsburgh School of Medicine (J.L.W.); and New England Medical Center Hospital, Boston (S.M.W.).

AJNR 15:1596-1600, Sep 1994 0195-61 08/94/1508-1596 © American Society of Neuroradiology

AJNR: 15, September 1994

Hematologic Disorders

Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises: N Eng/ J Med 1994;

330:920-927.

Bilateral epistaxis, retinal hemorrhages, and bilateral

central-retinal-vein occlusions were among the clinical

manifestations of "hyperviscosity syndrome." Plain films of skull and hip showed lytic foci. "A diagnostic procedure was performed": monoclonal protein identified in blood

and urine clinched the diagnosis of (did you guess?) mul-tiple myeloma.DJLW

Inflammatory Disease

Drobyski WR, Knox KK, Majewski D, Carrigan DR. Brief

report: fatal encephalitis due to variant B human

herpes-virus-6 infection in a bone marrow-transplant recipient.

N Eng/ J Med 1994;330:1356-1360.

This is the first documentation of central nervous system

infection by human herpesvirus-6. Autopsy revealed

dam-age to astrocytes and myelin in frontal white matter, and to neurons in hippocampus gray matter. Other herpesvirus infections have a propensity for the limbic system. Unfor-tunately, no imaging studies are included.DJLW

Gilden DH. Herpes zoster with postherpetic neuralgia-persisting pain and frustration. N Eng/

J

Med 1994;330: 932-933.

Postherpetic neuralgia is pain in one to three der-matomes after resolution of cutaneous herpes zoster in the

same distribution. Ongoing ganglion inflammation (zoster

sine herpete) may cause postherpetic neuralgia. Current

doses of oral acyclovir are not effective, but higher oral

doses, or intravenous therapy, may attenuate or eliminate

the pain. Good news for sufferers.DJLW

Mandible and Maxilla

Eisele DW, Richtsmeier WJ, Graybeard JC, Koch WM,

Zinreich SJ. Three-dimensional models for head and neck

tumor treatment planning. Laryngoscope 1994;

104:433-439.

Plastic mandibular models generated by three-dimen-sional computed tomography (CT) reconstruction and

dental impression type models of the maxilla were each

evaluated for usefulness for the head and neck surgeon.

The first type was expensive and technologically intensive

and the second type was simple but limited. Both models were valuable in certain clinical situations and both had disadvantages of cost, time, and possible inaccuracies

caused by image artifacts.DRBL

ANNOTATED BIBLIOGRAPHY 1597

Kuppersmith RB, Disher MJ, Deveikis JP, Frey K, Shulkin

BL, Clevens RA, Wolf GT. Management of an osteogenic

sarcoma of the maxilla. Ann Otol Rhino/ Laryngol 1994; 103:408-412.

Radionuclide bone scan, coronal CT, coronal pre- and

postcontrast T1-weighted MR, anteroposterior angiogram,

and a positron emission tomography scan are used to

illustrate this lesion. Approximately 10% of all osteosarco -mas are found in the head and neck region, most often in

the mandible or maxilla. All maxillary osteosarcomas are

believed to arise in the alveolar ridge. This case occurred

in a 35-year-old man with a 115-pack per year smoking

history who had undergone local excision of a smaller

tumor 2 years before.DJDS

Neck

and

Nasopharynx

Kerner MM, Bates ES, Hernandez F, Mickel RA. Carcino-ma-in-situ occurring in a Zenker's diverticulum. Am J Otolary ngol 1994; 15 ( 3): 223-226.

Zenker Pharyngoesophageal Diverticulum results from

an outpouching in the inferior constrictor muscle known as

Killian Dehiscence. The authors present the sixth reported

case of carcinoma-in-situ occurring within a Zenker

diver-ticulum. They emphasize that cigarette smoking,

hemop-tysis, previous upper-aerodigestive-tract malignancy, and a prolonged history of the diverticulum have been

identi-fied as risk factors.DJDS

Stack MC, Ridley MB. Spontaneous cervical emphysema

in a child. Otolaryngol Head Neck Surg 1994;110:318-323.

This is a long, mistitled case report of a child who

(pre-sumably) performed repeated Valsalva maneuvers,

caus-ing alveolar rupture. The authors state that all "spontane-ous" cervical emphysema has a cause "if closely studied."

Their bias is apparent: this is really an article on various causes of cervical emphysema. Captions for the two plain

films (neck, chest) and lung-window CT images (neck,

chest) describe arrows pointing to the emphysema, but the

arrows are nowhere to be seen.DJLW

Mori H, Nishimura Y, Satomi F, Mohri D, Kumoi T.

Recon-sideration on the hyoid syndrome. Otolaryngol Head Neck Surg 1994;110:324-329.

The authors present four cases, illustrated with three CT

images and one xeroradiograph. Each case (and figure)

purports to show an abnormally prominent greater cornu

of the hyoid. All patients had the offending greater cornu

removed, with relief of symptoms. Nonetheless, "hyoid greater cornu" syndrome, caused by irritation of the

sym-pathetic plexus around carotid artery or sinus branch of

glossopharyngeal nerve, remains unconvincing.DJLW

Deutsch ES, Milmoe G. Stridor in an adolescent: an

un-usual symptom. Otolaryngol Head Neck Surg 1994; 110: 330-332.

New-onset stridor in adolescents is rare. A 14-year-old

with stridor had a tracheal papilloma diagnosed on MR

(one sagittal image), fiberoptic bronchoscopy, and

frozen-section pathology. The final pathologic diagnosis was

mu-coepidermoid carcinoma of the trachea, which is rare, and

occurs most frequently in teenagers and young adults.

1598

ANNOTATED BIBLIOGRAPHY

Goepfert H

,

Callender DL. Differentiated thyroid

cancer-papillary and follicular carcinomas.

Am J Otolaryngol

1994;15:167-179.

More than 90

%

of thyroid carcinomas are

well-differen-tiated

. This

is a

thorough review

emphasizing

the

patho-genesis

, diagnosis

,

and

treatment

of

these lesions. Much

of

the information in this thorough review is highly pertinent

to

contemporary

head

and

neck radiology

.OJDS

Ophthalmologic Radiology

Zagelbaum

BM

,

Hersh PS, Donnenfeld ED

,

Perry HD,

Hochman MA

.

Occasional notes: ocular trauma in

major-league

baseball players.

N Eng/ J Med

1994;330:

1022-1023.

This (unintentionally?) amusing study presents

impor-tant findings. A 1-year prospective

study

found 24

eye

injuries

in

21

major-league players, or 1.9

eye

injuries per

100,000

"player-innings."

Batted balls, eye-rubbing,

for-eign

bodies, and the shortstop's

knee

accounted for most

of

the

injuries.

Of the

21

players

,

only one wore safety

glasses!

These players

'

potential to influence

eye-protec-tion habits by setting a

(good)

example is (as it were)

overlooked

.D

JLW

Nose, Paranasal Sinuses, Face, and Oral

Cavity

Ferguson BJ. Fibrous dysplasia of the paranasal sinuses.

Am J

Otolaryngo/1994;15:227-230.

Fibrous dysplasia involving the paranasal sinuses is a

rare

subset of

craniofacial

fibrous dysplasia

.

Medullary

bone is replaced by structurally

unsound

fibroosseous

tissue. This may result in recurrent infections

,

mucocele

formation, nasal

airway obstruction,

and facial pain. An

excellent

and

well-illustrated

review presenting two

origi-nal

cases clearly

defined with high quality CT scans.

O

JDS

Pediatric Neuroradiology

Torres

CT,

Rebsamen

S,

Silber JH

,

et al.

Surveillance

scanning of children with medulloblastoma.

N Eng/ J Med

1994;330

:

892-895

.

This retrospective

study

compared "surveillance

scan-ning

"

(CT

,

MR) to history and physical

examination

for

detecting tumor

recurrence

after therapy

for

medulloblas-toma

(posterior fossa primitive neuroectodermal

tumor).

Of

86 children

,

four (clinically asymptomatic)

recurrences

were

detected by

scans, and 19 recurrences were

detected

clinically. One problem with

the

study is that

MR,

intro-duced during

the

study period ( 1980-1991),

might have

detected disease

missed

on

CT.

The authors acknowledge

this

.

Their conclusion

,

that surveillance scanning

has

lim-ited clinical

value,

is debatable

,

because they studied

a

tumor for which cure after

recurrence

is,

in

their words

,

"rare."OJLW

AJNR: 15, September 1994

Lee N

,

Radtke RA

, Gray L

,

et al.

Neuronal migration

dis-orders: positron emission tomography correlations

.

Ann

Neural

1994

;

35:

290

-297

.

The

extent of

neuronal migration disease is important in

surgical

planning for

epilepsy

patients because the best

prognosis is seen when the lesion and epileptogenic region

are completely

removed

.

lnterictal FOG-positron emission

tomography findings were

correlated

with MR findings

in

17

epileptic

patients

with

neuronal migration disorders. Fifteen

patients with abnormal MR findings had focal

hypometa-bolic regions in nine

cases

and a unique finding of

dis-placed metabolic activity of normal gray matter in six

cases

.

Three

of

the nonhypometabolic

cases

showed larger

lesions on positron emission tomography

than on

MR.ONA

Renowden SA

,

Squier M

.

Unusual magnetic resonance

and neuropathological findings

in

hemimegalencephaly:

report

of a case following hemispherectomy.

Dev Med

Child Neural

1994;36:357-369.

Neuropathologic tissue obtained at the time

of

hemi-spherectomy from a 15-year-old with

hemimegalen-cephaly

and persisting seizures is

correlated

with MR

im-aging

alteration.OJAB

Cohen M, Roessmann U. In utero brain damage:

relation-ship of gestational age to pathological consequences.

Dev Med Child Neural

1994;36

:

263-170.

Two

episodes

of intrauterine asphyxia are

correlated

with

neuropathologic findings and with a review of the

literature

.

Although intensity and duration of asphyxia is

difficult to

characterize,

insults

occurring

before 24 weeks

of

gestation had bilateral pallidal necrosis as a common

feature, while an insult between 26 and 34 weeks of

ges-tation was

commonly

associated

with

thalamic and

brain-stem necrosis

.

No images are included.OJAB

Moller JR, Trapp BD

,

Schiffmann R,

et

al. Childhood ataxia

with diffuse central nervous system hypomyelination.

Ann

Neuro/1994;35:331-340.

Four patients demonstrate diffuse white matter disease

of the

cerebrum

and parts of the cerebellum on CT and MR

examinations

with minimal clinical findings

.

Progressive

clinical

leukodystrophy was identified without

abnormali-ties found in the

evaluation

for

known

metabolic and

de-generative diseases. This progression was not reflected

on

the MR or CT

examinations.

MR spectroscopy

demon-strated

marked decrease in the N-acetylaspartic acid

,

cho-line

, and

creatine

of the white matter relative to gray

mat-ter. This appeared to be specific

in

this distinct clinical

pathological

syndrome, because it has not been previously

reported

in

other white

matter diseases

.O

NA

Phakomatoses

North

K,

Joy P,

Yuille

D

,

et al. Specific

learning

disability

in

children

with

neurofibromatosis type

1:

significance of

MRI

abnormalities

.

Neurology

1994;44:878-883.

An interesting

paper. Patients

with

neurofibromatosis

type

1 and focal areas of

high

intensity

on T2-weighted

MR

had a

much higher

risk for impaired academic

achievement than

patients

with

neurofibromatosis

type 1

who

did not have the T2

changes.

Furthermore

,

the

fre-quency

of

learning disability in the neurofibromatosis

pop-ulation

was

much higher

than that

expected for the

general

AJNR:

15,

September 1994

Seizure Disorders

Cendes F

, Andermann F, Preul MC, Arnold DL.

Lateraliza-tion

of temporal lobe epilepsy based on regional

meta-bolic abnormalities in

proton

magnetic

resonance

spec-troscopic

images.

Ann l'leurol

1994

;35:211-216.

Lateralization of temporal lobe

epilepsy of 10

patients

who had surgical treatment

of medically

intractable

epi-lepsy

was compared

with findings in 5 healthy

control

subjects

using the

reduced

N-acetylaspartate-to-creatine

ratio

.

This ratio showed agreement with the side of

clinical-electroencephalogram lateralization and MR abnormalities

in

all cases.

One patient had no MR abnormalities but

showed MR spectroscopy abnormalities confirmed

patho-logically as mild hippocampal sclerosis,

suggesting

that

MR spectroscopy may be

able

to show neuronal loss in

these patients

with

a greater sensitivity than MR.D

NA

Cook MJ

. Mesial temporal sclerosis and volumetric

inves-tigations.

Acta l'leurol Scand Suppl

1994

;89

(152):109-114.

This paper,

in

an

Acta l'leurologica

volume

devoted to

epilepsy

surgery, regards the value

of volumetric MR

ex-amination

of

the mesial temporal lobe

structures

in

patients with clinical temporal lobe seizures. Numerous

papers on the neurophysiology

,

value of

subdural

electrodes,

magnetic

source

imaging

, MR, and functional

changes including positron emission tomography

in

patients with temporal lobe problems

are

discussed in

this volume.DSMW

Kitchen ND, Thomas DGT, Shorvon SD, Fish DR, Stevens

JM. Volumetric analysis of epilepsy surgery resections

using high resolution magnetic imaging: technical report.

BrJ l'leurosurg

1993

;7:651-656.

A technique for

obtaining accurate

baseline

postopera-tive

examinations

with a volumetric MR technique

was

used in 25 patients. This method lends itself to further work

to' evaluate the efficacy of lesionectomy versus an en-bloc

resection as related to the volume

of

brain removed and

the long-term functional follow-up

.D

NA

Jack CR, Mullan BP, Sharbrough FW, et

al. Intractable

nonlesional epilepsy of temporal lobe origin: lateralization

by interictal SPECT versus MRI.

Neurology

1994;829-836.

The authors found that MR

of the temporal lobe is

more

accurate than single-photon emission CT in

providing

ac-curate seizure lateralization. More specifically

,

hippocam-pal volume measurements correctly

lateralized seizures in

86% of

cases,

whereas single-photon

emission

CT

cor-rectly lateralized seizures in 45% of cases.

D

SMW

Jackson GD, Connelly A,

Cross JH, Gordon I

,

Gadian DG

.

Functional magnetic resonance imaging of focal seizures.

l'leurology

1994;44:850-856

.

An interesting

case report of a

patient

with seizures

studied with

a conventional 1.5T MR

system with a flash

sequence. The

images acquired every 10 seconds in

blocks of 60 images were obtained during clinical seizures

and showed sequential

activation associated with specific

gyri.DSMW

ANNOTATED

BIBLIOGRAPHY

1599

Garcia

PA,

Laxer

KD, van der Grond J

,

et

al. Phosphorus

magnetic

resonance

spectroscopic

imaging

in patients

with frontal lobe

epilepsy.

Ann

1'/

e

uro/1994;35

:2

17-221.

Phosphorus MR

single-photon emiss

ion CT was used

in

e

ight patients with frontal lobe epil

epsy determined by ictal

electroencephalogram recordings and with normal MR

findings

.

Within the epileptogenic frontal

lobe

the mean

pH

was significantly

increased

in

five patients

compar

e

d

with

the

contralateral frontal

lobe

and with

control

sub-jects. The

phosphomonoester

levels

were decreased

asymmetrically,

c

orrectly

lateralizing

the frontal

epil

epto-genic

foci in

seven of eight patients.

The mean inorganic

phosphate levels

failed

to

provide

lateralizing

informa

-tion

,

because they

were

not consistently

increased within

the epileptogenic focus as in patients with temporal lobe

epi-lepsy

.D

NA

Spine

Ditunno JF

,

Forma CS.

Current concepts: chronic spinal

cord injury.

1'1

Eng/ J fVled

1994

;

330

:

550-557

.

The

authors of

this interesting paper

are

rehabilitation

physicians

.

They

discuss

pathophysiology

,

manifesta

-tions,

and management of complications encountered

both in the

second year and

more than

30 years after

spinal cord

injury. Psychosocial issues include

employ-ment,

sexual

function,

parenthood,

aging

,

and

life

satis

-faction

.

These

are

important

clinical correlates of

condi-tions neuroradiologists

often

diagnose without pausing

to

consider the

ramifications.

D

JLW

Zimmerman GA, Weingarten K

,

Lavyne MH

. Symptomatic

lumbar epidural varices: report of two cases

.

J 1'/eurosurg

1994;80

:

914-918

.

Describes a

rare cause of back pain with good

imaging

findings,

color operative

photos

,

and

discussion. I

had

never heard of this entity until I encountered my first

case

about 3 years ago.DADE

Barnsley L,

Lord SM,

Wallis BJ

,

Bogduk N

.

Lack of effect

of

intraarticular

corticosteroids

for

chronic pain

in the

cervical zygoapophyseal joints.

1'1

Eng/ J fVled

1994;330:

1047-1050

.

Patients

with chronic

neck

pain after whiplash under

-went a

therapeutic trial injection

of

local

anesthetic

into

dorsal

rami supplying cervical zygoapophyseal

joints. If

their pain

diminished

,

they were

randomized

into a group

that received bupivacaine or a group that received

beta-methasone

(local anesthetic or steroids introduc

e

d

into

zygoapophyseal joints under fluoros

co

pic

guidance)

.

Du-ration of pain relief was 3.5 days for

bupivaca

ine, 3.0 days

for betamethasone. The authors conclude that

intraarticu-lar

steroid therapy

is not worth the risk and radiation

ex-posure.

The

study is nicely

designed

,

the

disc

ussion

is

thoughtful

and thought-provoking

.D

JLW

Carette S. Whiplash injury and chronic neck pain.

1'1

Eng/

J fVled

1994;330

:

1083-1084.

This

accompanying

editorial

provides

some

interesting

statistics on

"

late whiplash syndrome

."

The

a

uthor firmly

states that there

is

now enough

ev

iden

ce that steroid

in-jection into apophyseal joints is ineffective

.

He believes the

practice

should

be

stopped, perhaps by discontinuing

third-party

reimb

ursement

.

An une

x

pected proposal!

1600

ANNOTATED BIBLIOGRAPHY

Stroke

Jansen C, Ramos LMP, van Heesewijk JPM, Moll FL, van

Gijn J, Ackerstaff RGA. Impact of microembolism and hemodynamic changes in the brain during carotid endar-terectomy. Stroke 1994;25:992-997.

Pre- and postoperative CT or MR was monitored in pa-tients undergoing carotid endarterectomy, with monitoring of the endarterectomy with transcranial Doppler. There was a significant correlation between the number of em-bolic signals during surgical dissection of the carotid artery and occurrence of intraoperative infarcts. Two MR figures. OJSR

Grasso MG, Pantano P, Ricci M, et al. Mesial temporal cortex hypoperfusion is associated with depression in subcortical stroke. Stroke 1994

;254:980-985

.

Fifteen patients with a single subcortical lesion were evaluated for depression as well as with single-photon

emission CT using 99mTc hexamethylpropyleneamine

oxime. A number of flow values were lower in the de-pressed patients than the nondepressed, only in the mesial temporal cortex of the affected hemisphere. Authors sug-gest the temporal lobe hyperperfusion reflects dysfunction of the limbic system, which may underlie depressive phe-nomenology. Two color single-photon emission CT figures.DJSR

Gideon P, Sperling B, Arlien-Soborg P, Olsen TS, Henriksen 0. Long-term follow-up of cerebral infarction patients with proton magnetic resonance spectroscopy. Stroke

1994;25:967-97

3

.

Six patients with ischemic stroke were evaluated in the acute stage to the chronic stage with proton MR spectros-copy. No clear correlation was found between the level of N-acetylaspartate or lactate in the acute stage of stroke and the clinical outcome. However, the study group is too small to draw any definite conclusions regarding the prog-nostic information of spectroscopy. OJSR

Tempora

l

Bone

Katsarkas A. Dizziness in aging: a retrospective study of

1194 cases.

Otolaryngol Head Neck Surg

1994

;

110:296-30

1.

This is a frustratingly vague retrospective study of 1194 patients who were

70

years or older when first seen at a "dizzyness clinic." Odd results:

2

1% of patients remain

ed "undiagnosed;"

3

9% wer

e "strongly suspected" of having paroxysmal positional vertigo. "Cardiovascular" causes are included with the 8

.7% with

"nonvestibular, non-neu -rologic" disease, but another

6.

3%

were diagnosed with "cerebrovascular disease." This distinction is not ex -plained. Seventeen patients had tumors: "most" were acoustic neuromas or meningiomas. It is unclear when (and which) imaging studies were used. The conclusion restates the introduction. What has been learned?OJLW

AJNR:

15,

September 1994

Spingarn AT, Selesnick SH, Minick CR. Inner ear cho -lesteatoma: an embryologic aberration. Otolaryngol Head Neck Surg

1994; 110:333-337.

This supposed primary cochlear cholesteatoma caused tinnitus, hearing loss, dysequilibrium, and ear pain. The MR (included) showed intense enhancement of the co-chlea, vestibule, semicircular canal, and fundus of the internal auditory canal. The CT (included) showed erosion of the otic capsule. (Close examination of the MR suggests erosion of the otic capsule.) This wordy case report dis-cusses hypotheses on the causes of primary chol esteato-mas and epidermoids: metaplasia, aberrant differentiation in utero, aberrant migration, aberrant inclusion of epithe-lium. The authors admit their case remains puzzling. Per-haps this was a middle ear cholesteatoma after all? Per-haps the pathologic diagnosis is inaccurate?OJLW

Kavanaugh KT. Applications of image-directed robotics in otolaryngologic surgery. Laryngoscope

1994;

104:283-292.

Using image-directed robotics, antrostomies were per-formed on five human temporal bone specimens. The antrum was reached in all bones. The dura, horizontal canal, sigmoid sinus, and facial nerve were not violated in any specimen. The average absolute error in bone removal was 0

.

88 mm

. The use of a robotic arm with tighter joints and redundant position checking should overcome most of these problems.DRBL

Moreano EH, Paparella MM, Zelterman D, Goycoolea MV.

Prevalence of facial canal dehiscence and of persistent stapedial artery in the human middle ear: a report of 1000 temporal bones. Laryngoscope

1994; 104

:309

-

320

.

A total of 1 000 temporal bones were examined to study the prevalence of facial canal dehiscence and persistent stapedial artery. At least one facial canal dehiscence was present in

56%

of the temporal bones most commonly near the oval window. There was a

76

%

prevalence of bilaterality of this finding. Microdehiscence of the facial canal was present in

75% of specimens with a

40%

bilat-erality. Persistent stapedial artery was present in 0.48% of the specimens.DRBL

Trauma

Young WB, Silberstein SD. Imaging and electrophysi-ologic testing in mild head injury. Semin

Ne

uro/1994

;14:

46

.