Linguistic differences between a developmental language impairment and

Thus far, it has been discussed how cognitive communication disturbances

can occur after a TBI, with specific frontal lobe damage being a major contributor in

discriminating some of the cognitive difficulties present in someone with a TBI. It is

also apparent that children with a DLI present with communication impairments that

may be associated with impaired cognitive functioning. However, there are no known

studies comparing the two groups in paediatrics or adults on standardised

assessments. When a child or adult has sustained a TBI, it may be possible to

In contrast to a TBI, there is no baseline of communication skills to compare pre and

post-DLI. However, for children who experience a TBI at a very young age where

communication skills have not started developing, there may also be little opportunity

to measure communication ability prior to the injury. Similarly, in both TBI and DLI,

the gap between academic and social communication skills with peers can widen

over the course of their development, (Anderson et al., 2012; Poll, Betz, & Miller,

2010). TBI has been characterised by a continuum of severity and clinical

presentation resulting in a heterogeneous population (Chapman, 1997; Turkstra,

Coelho, & Ylvisaker, 2005a). This heterogeneity is also a feature of DLI (Webster et

al., 2006). That is, children with a TBI or DLI could have language deficits across all

areas, or in specific areas, such as vocabulary or pragmatics for example. In

addition, language delay or disorder could be greater in one child than the other meaning they don’t all present with the same issues in communication, or perform

the same on language tests. In addition, cognitive deficits could differ in severity

between children with TBI and DLI, or they might have specific cognitive strengths or

weaknesses in areas such as attention or executive functions, and this has been

highlighted in studies examining the variability in cognitive abilities in children with

TBI (Conklin, Salorio, & Slomine, 2008) and DLI (Archibald & Gathercole, 2006).

Thus, neither TBI or DLI should be treated as homogenous within each group and,

as such, the assessment should be targeted to the needs of the individual.

Studies directly comparing the linguistic performance of adults or children with

a TBI and/or a DLI are limited (Chapman, 1997; Sullivan & Riccio, 2010), but

different clinical markers for English speakers in each group have been noted.

Clinical markers in DLI, including difficulties with morphology (Poll et al., 2010),

singular (Conti-Ramsden et al., 2001; Simkin & Conti-Ramsden, 2001), have been

shown to be the same both in adults and children who have a DLI. Difficulties in

vocabulary and pragmatics may be evident, but these types of tasks may not be the

most sensitive tasks to identify a child with a DLI (Leonard, 2000; Webster et al.,

2006). Studies comparing DLIs with other disorders, such as autism, have shown

that children with a DLI are more likely to perform more poorly on a range of

language tasks that cover vocabulary, syntax, morphology, and pragmatics (Demouy

et al., 2011; Webster et al., 2006). Moreover, whilst children with a DLI initially have

difficulties with oral language, their difficulties broaden to include reading and written language (Friel-Patti, 1999). The SLP’s role in assessment often includes reading

and written language (Owens, 2014) which has expanded from articulation,

phonology, and oral language, which might have been historically seen as the more

traditional SLP roles (ASHA, 2010). Aspects of language, communication, and

literacy assessed by SLPs will be discussed later in this chapter.

In contrast to a DLI, where there are difficulties with general aspects of

language, any individual with a TBI is more likely to have difficulties with more subtle

aspects of language and communication (Chapman, 1997; Sullivan & Riccio, 2010).

These include areas of semantics such as lexical comprehension or production

(Ewing-Cobbs & Barnes, 2002) and pragmatics (MacLennan et al., 2002; McGrane &

Cascella, 2000). These difficulties are seen more at the level of discourse both in

children (Cook, Chapman, & Gamino, 2007) and adults (Coelho, 2007). However

with children, the complicated challenge for the SLP is that age of injury can impact

on the severity of language and cognitive communication skills (Crowe, Catroppa,

Anderson, & Babl, 2012), so initially, consequences of the TBI in a number of areas

begins to develop more skills, new learning is compromised, due to the variety of

cognitive processes, such attention, memory, processing speed and executive

functions that can be impaired after a TBI (Mandalis, Kinsella, Ong, & Anderson,

2007). These cognitive deficits impacts on what the child can process or encode and

or consolidate, store or recall when information presented to them. Thus the

trajectory of development may be slower as the longer-lasting effects of the injury

become more apparent (Chapman, Nasits, Challas, & Billinger, 1999; Vu, Babikian,

& Asarnow, 2011).

Word-finding, high-level language, and pragmatic skills are specific areas of

language compromised even by a mild TBI (Hough, 2008; Turkstra, McDonald, &

Kaufmann, 1996) (Duff, Proctor, & Haley, 2002; King, Hough, Walker, Rastatter, &

Holbert, 2006). Areas of language where there are difficulties are often similar irrespective of the individual’s age. However, as noted before, the age of the injury

may impact on the development of language skills, so a child with a TBI who was

injured in preschool or younger can present with more significant receptive and

expressive language difficulties (Sullivan & Riccio, 2010). It is yet to be studied

whether such difficulties with general language abilities are similar to the effects of a

DLI, but some small studies have shown that vocabulary and not grammatical

development is more affected in early TBI (Crowe, Anderson, Barton, Babl, &

Catroppa, 2014; Trudeau, 2000). In one such study by Trudeau (2000) a case study

was used of a child with a TBI and was assessed over a period of 6 months and this

was compared to two control groups (n=5 and 9). In this study, vocabulary scores

were significantly below the control group, whereas verbal complexity and mean

The school-aged child with a TBI may have preserved ability to construct

sentences and use appropriate grammatical structures (Chapman, 1997). Because

of this, conversational language including pragmatic skills such as turn-taking, topic

maintenance, or gist and summarising should be assessed (Cook et al., 2007). As

mentioned earlier, new learning can be impacted, thus impeding vocabulary

development. As a result, as the child matures, high-level language skills such as

humour (Docking, Murdoch, & Jordan, 2000), figurative language (Yang, Fuller,

Khodaparast, & Krawczyk, 2010), and inferential reasoning (Dennis & Barnes, 1990;

Dennis & Barnes, 2001) should be targeted areas of assessment. In addition, for

children who sustain their TBI in their school years, written language has been

identified as an area of weakness (Yorkston, Jaffe, Liao, & Polissar, 1999; Yorkston,

Jaffe, Polissar, Liao, & Fay, 1997) as have reading comprehension skills (Dennis &

Barnes, 2001). Decoding skills have been identified as an area of weakness for

children with a TBI if the injury was sustained prior to early literacy development

1.5 Importance of a clinical assessment for language and cognitive