Introduction

The following exercise is a case study of a man (‘DL’) aged 47 years who was studied by Smith Doody et al. (Reference Smith Doody, Hrachovy and Feher1992). DL developed temporal lobe epilepsy subsequent to encephalitis. He exhibited recurrent fluent aphasia in association with his temporal lobe seizure activity. Post-encephalitic epilepsy is a relatively common neurological disorder which has implications for speech and language. It is thus a disorder which falls within the professional remit of speech-language pathologists. The case study is presented in five sections: primer on post-encephalitic epilepsy; medical history; cognitive assessment; language assessment; and focus on expressive language.

Primer on post-encephalitic epilepsy

Adult-onset epilepsies can be caused by a number of diseases and injuries. These epilepsies may arise on account of cerebral infections like viral encephalitis and bacterial meningitis. They may also be caused by cerebrovascular disease, tumours, neurosurgical procedures and traumatic brain injuries. Epilepsy is a relatively common neurological sequela in adults who develop encephalitis. Singh et al. (Reference Singh, Fugate, Hocker and Rabinstein2015) examined 198 adults aged 41 to 69 years with acute encephalitis. These investigators reported post-encephalitic epilepsy in 29.9% of patients. Seizures were most commonly found in adults with auto-immune encephalitis (54.5%). However, viral encephalitis (24.2%) and encephalitis of unknown or other aetiology (33.9%) were also associated with seizure activity. Encephalitis is increasingly being linked to adult-onset temporal lobe epilepsy. Bien et al. (Reference Bien, Urbach, Schramm, Soeder, Becker, Voltz, Vincent and Elger2007) examined 38 patients with temporal lobe epilepsy whose median age at onset was 37.8 years. Nine patients (24%) had a diagnosis of definite auto-immune encephalitis, and a further 11 patients (29%) had a diagnosis of possible auto-immune encephalitis. In a study of 74 adults who underwent temporal lobectomy, Uesugi et al. (Reference Uesugi, Shimizu, Maehara, Arai, Kaito, Matsuda, Nakayama and Onuma1998) related the onset of temporal lobe epilepsy to undiagnosed episodes of mild encephalitis/meningitis in childhood.

Post-encephalitic epilepsy is associated with a range of language and cognitive problems. Kishi et al. (Reference Kishi, Sakakibara, Ogata and Ogawa2010) reported the case of a 59-year-old woman with limbic encephalitis who presented with severe anterograde and retrograde memory impairment and transient fluent, phonemic paraphasia. Bianchi et al. (Reference Bianchi, Dworetzky and Bromfield2009) examined five patients with adult-onset, medically intractable, post-encephalitic epilepsy. These patients experienced auditory auras which ranged from unformed buzzing to structured language. Okuda et al. (Reference Okuda, Kawabata, Tachibana, Sugita and Tanaka2001) reported the case of a 25-year-old woman who developed pure anomic aphasia following encephalitis. The patient's naming difficulty persisted during a two-year follow-up period in the absence of any other language or memory dysfunction.

Medical history

DL is a 47-year-old, right-handed, Hispanic man. In March 1988, he experienced a headache. This was followed by fever and a right focal seizure which then generalised. He was admitted to hospital with a diagnosis of encephalitis. After discharge, he did well for a 2-month period but was then readmitted for the sudden onset of confusion. A left frontal brain biopsy was performed, but it was non-diagnostic. DL was discharged on Dilantin and phenobarbital. He was admitted again seven months later for worsening mental status and received a 10-day course of acyclovir. Over time, DL improved to a baseline of good functioning but he was unable to return to work. His family reported that he understood all but the most difficult discussions and continued to read. Apart from his finances, which he was not able to handle without assistance, DL was able to take care of his usual activities. His medication at this stage was 200 mg Dilantin by mouth twice a day. Phenobarbital was being tapered.

On 23 September 1989, DL was admitted to the Houston Veterans Affairs Medical Center for the sudden onset of altered mental status. That morning, he had been feeling well and was talking to his family about job prospects. They left him and returned half an hour later to find him crying and confused. He was unable to explain what was wrong. An examination of his mental status in hospital revealed him to be alert but disoriented to person, place, time and situation. He displayed a receptive aphasia. A general physical examination was normal. A general neurological examination revealed only a slight circumduction of the right lower extremity. CBC (complete blood count) and SMAC (a broad screening tool to evaluate organ function) were normal. Thyroid function tests, vasculitis screen and cerebrospinal fluid examination were also normal. An MRI showed a slight, generalised increase in ventricular size but no other focal abnormalities since his post-craniotomy study performed 16 months earlier. An EEG was conducted the morning after admission. There was recurrent moderate to high voltage spike, and slow and sharp and slow wave activity in the left temporal region which occurred every 1 to 3 seconds. Two episodes of staring with unresponsiveness occurred on the second hospital day. These correlated with continuous spike and wave discharges in the left temporo-occipital region on EEG. DL was given 10 mg of Valium without clinical effect. He was loaded with 500 mg Dilantin and 60 mg phenobarbital. In a follow-up EEG, there was a left temporal slow wave focus with frequent spikes and sharp waves and a normal background.

Cognitive assessment

Early on the fifth day of hospitalisation, DL's cognitive skills were assessed using the Mini-Mental State Examination (MMSE; Folstein et al., Reference Folstein, Folstein and McHugh1975). This assessment contains five subtests: orientation; registration; attention and calculation; recall; and language. DL spelled the word ‘world’ backwards quickly and without errors, but made two errors when he attempted to state the months of the year backwards. When questioned in writing, he was fully oriented (he scored 9/10 correct). However, he did not comprehend the orientation questions when orally questioned. He was able to copy the drawing on the MMSE correctly. Comprehension difficulties precluded an assessment of visual memory and verbal memory. He was accurate on the Digit–Symbol substitution subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R; Wechsler, Reference Wechsler1981). DL was unable to complete the sequence 1–A, 2–B, 3–C, and so on. He made three omission errors on the ‘A's test’ of vigilance. DL displayed inconsistent insight into his situation.

Language assessment

DL's language skills were also extensively examined. On the Boston Diagnostic Aphasia Examination (Goodglass and Kaplan, Reference Goodglass and Kaplan1983b), DL displayed moderate auditory comprehension deficits. He was able to understand simple one- and two-step commands and displayed intact comprehension of 2 of 5 sentences. Repetition was very impaired – he was not able to repeat any sentences presented to him. DL was able to read aloud 5 of 7 sentences, with evidence of mild, occasional paraphasias. His reading comprehension was mildly impaired – he was able to understand 5 of 7 commands. On the Boston Naming Test (Kaplan et al., Reference Kaplan, Goodglass and Weintraub1983), DL named only 18 of 60 items. DL's spontaneous language production is examined in unit 20.5.

At the end of testing, DL laughed suddenly, stood up, stared and exhibited motor automatisms (eye blinking, picking movements with his fingers). He could only respond to questions with ‘yes’ or ‘si’. He was led back to his bed. When this period of staring and reduced responsiveness had passed, DL's aphasia was much worse. He was alert and was attempting to communicate. He used gestures to express his frustration. Orientation and memory testing were not possible as he did not appear to understand what was required of him. His speech, which had been previously fluent, was almost completely neologistic and unintelligible. His verbal comprehension was markedly decreased, and he understood no verbal commands. During reading aloud, he produced neologistic jargon. He was still able to copy a drawing. On occasion, he stopped talking and blinked for a few seconds. During this period, a bedside EEG revealed seizure activity in the left temporal region.

Focus on expressive language

This unit contains three extracts of expressive language produced by DL. These extracts are taken from: (1) the session during which DL's history was taken; (2) the session during which language testing was performed; and (3) DL's attempt to describe the cookie theft picture. Although these extracts are short, they are nonetheless revealing of DL's language problems.