A Case of a Vietnam War Veteran with Early-Onset Huntington’s Disease

Abstract

We report on the case of Simon (his pseudonym). We describe the presentation of early-stage late-onset Huntington’s disease (HD) in a man with multiple psychiatric diagnoses. Our clinical problem was ‘To what extent are common psychiatric features masking a further diagnosis?’ Initially unwilling to be tested for HD, he agreed on condition that it assists with his discharge plan.

Introduction

Huntington’s disease (HD) presents with cognitive changes in its early stages, before more serious manifestations of psychiatric and physical changes. Typically presenting in the third decade of life, occasionally HD presents in the sixth or seventh decade of life. Depressive symptoms and cognitive changes present ahead of physical changes. Physical symptoms are mostly jerky and uncontrollable movements that develop into a chorea. Small movements precede more significant changes by at least 3 years. ¹ While ample literature illustrates the development of HD in younger patients, few examples illustrate the development of HD in the sixth of decade of life where pre-existing psychiatric and medical signs could mask early manifestation and exclude patients from clinical trials.

Case Description

Simon is a 67-year-old single man, living independently, before his sister brought into a public hospital because of his reportedly deteriorating mental state. Preliminary tests ruled out acute pathology. A head computed tomography (CT) confirmed that he had no acute intracranial pathology. His medical history included tinnitus, hypertension, and obstructive sleep apnoea. Simon was transferred to a private hospital where during several previous admissions he had been diagnosed with post-traumatic stress disorder (PTSD) and major depressive disorder, mostly stemming from his conscripted service in the Vietnam War. Simon was later diagnosed with dependent personality disorder when admitted to a Forensic Unit after crashing his car into the family home following a marital break-up; this incident also attracted an 18-month prison term. Subsequently, the Department of Veteran Affairs deemed Simon permanently incapacitated. During his Australian Defence Force employment, Simon had qualified and worked as an engineer.

Assessment

During admission interview, Simon reported that he had been renting a room from a couple who did not support his psychiatric diagnosis, stating his antidepressant medication was ‘evil’. Whereupon, the patient had ceased all medication and commenced herbal supplements; his depressive symptoms including low mood, poor concentration, agitation, and disrupted sleep returned. He referred to his brother’s recent death but stated the cause was unknown. Simon was tangential and difficult to guide but had no other signs of mood elevation. He denied any manic symptoms. He was observed to have an atypical gait and jerky head and neck movements. Medical review noted Simon’s decreased verbal fluency and finger agnosia.

Management

Simon was recommenced on antidepressant medication with good relief from his depressive symptoms. However, Simon remained confused and tangential in conversation with apparent ongoing fidgeting. He required direct and repeated guidance in interview. Simon did not require medication to sleep and engaged in solitary activities during the day. Subsequent interviews revealed he had mild word finding difficulty and voluble discussion, but no signs of pressured speech and increased tone or volume. Although Simon’s responses lacked fluency, they were not inappropriate.

On the Montreal Cognitive Assessment, he scored 22 out of 30, indicating a decline in executive functioning. His Alcohol Withdrawal Scale was insignificant. A magnetic resonance imaging (MRI) showed mild ischaemic change, but no other changes were evident. Simon responded well to his psychotropic medication and denied any psychiatric symptomology; however, the treating team faced challenges in discharge planning for a patient who required additional support without an apparent cause for his decline.

Further discussion between the social worker and Simon’s sister revealed that their brother had died from HD. Another sister had been similarly diagnosed. Both siblings had developed symptoms in the sixth decade of life. Genetic testing showed that another 4 siblings were unaffected. While supportive of Simon, his sister stated she was unable to offer him accommodation. Simon was concerned about his accommodation on discharge.

Neurological Review

A neurologist’s examination noted that Simon had slurred speech and difficulty in sitting still. The neurologist highlighted that testing could result in accommodation support that would be beneficial to him and his family. Simon, who had previously refused genetic testing because of the absence of a cure, agreed to testing for the purposes of treatment planning. Genetic testing detected 2 alleles with CAG lengths of 41 ± 1 on and 29 ± 1, confirming the diagnosis of HD.

A neuropsychiatrist review noted the patient had shallow affect with frequent incongruous smiles. Simon reported ongoing mood dysregulation and frequent angry outbursts. His speech was noted to be difficult to follow and consequently a cognitive assessment was not possible. He was categorised as ‘markedly ill’ according to the Brief Psychiatric Rating Scale (with a score of 54) with evidence of bizarre thought content, excitement, and conceptual disorganisation. His Unified Huntington’s Scale motor score was 16. He had a mild but recurrent chorea and slight rigidity of the left arm and an impaired Luria fist–hand–palm sequencing indicating decreased executive function. He was judged to be in the early stages of HD.

Based on Simon’s confirmed diagnosis, the Aged Care Assessment Team (ACAT) assessment team quickly arranged a high level of support. Treatment planning was discussed at a family meeting with Simon: he was advised of his likely prognosis and advised to write an advanced health directive. The family was also advised to contact the HD support group.

Discussion

This case study demonstrates the detection and management of early-stage late-onset HD in a man with multiple psychiatric diagnoses. Recent studies which examined postural, cognitive, language, and performance indicators of early-stage HD are relevant.

Salomoncyzk et al ² retrospectively examined the postural changes associated with the progressive disease by altering the somatosensory, visual, and vestibular information accessible to 50 participants using the Sensory Organization Test. Participants included 11 individuals with manifest HD and 22 with pre-manifest HD for comparison with a control group. Retrospective data analysis showed that changes in proprioceptive information resulted in a significant postural sway in participants who developed manifest HD less than 5 years after the test was performed.

Using the Tower of London test, Morkl et al ³ examined cognitive capacity in early- and late-stage HD. Specifically, the test examines behavioural inhibition, impulsivity, and planning as measures of cognitive performance of individuals with HD. Deterioration in cognitive function, an early warning signs of HD, may precede other symptoms by up to 10 years. The researchers compared the performance of 23 early-stage participants with 29 late-stage participants and 34 controls on the executive function task, specifically testing for three measures: number of problems solved, total planning time, and total number of breaks taken. Researchers found a decrease in accuracy in both early- and late-stage HD when compared with control participants. They hypothesised that the degeneration of the dorsal caudate and the dorsolateral prefrontal cortex known to occur in the early stages of HD resulted in decreased accuracy. Furthermore, in both early-stage HD and late-stage HD, planning time decreased irrespective of complexity of the task which correlated with increased error, suggesting an increase in impulsivity even in the early stages.

Vogel et al ⁴ compared speech disturbances in pre-manifest and manifest HD carriers with 30 healthy controls. Participants’ speech was analysed for timing, frequency, and intensity. Participants carrying the HTT gene presented with slower rates of speech, took longer to say words, and produced greater silences between and within words compared with healthy controls. The speech of early-stage HD differed significantly from controls. The speech of pre-onset HD did not differ significantly from controls; however, they did exhibit traits comparable with those of early-onset HD.

Hart et al ⁵ followed pre-manifest and manifest HD participants more than 10 years and compared them with healthy controls for motor, cognitive, and behavioural performance. Participants were assessed at the commencement of the study, after 1.5, 3, 7, and 10 years. Of the 3 groups, the only group to show significant deterioration more than the 10 years was the pre-manifest HD group whose signs had become manifest. These participants showed greatest decline in executive function (demonstrated by performance on the Stroop Test, the Symbol Digit Modalities test, and Letter Fluency and Trail Making test) and memory (tested with the Wechsler Memory Scale and the California Verbal Learning test) closer to onset of the condition. Pre-manifest participants who remained pre-manifest throughout the study failed to show such a decline in executive function or memory. The comparatively normal baseline scores of participants far from onset suggest that both domains are largely unaffected at that stage. Unsurprisingly, the memory of manifest HD carriers deteriorated significantly more than the 10-year period but not as significantly as those pre-manifest participants who converted to the manifest group.

Simon’s apparent decline in cognitive functioning, speech, and gait in contrast with his normal MRI are clinical indicators that he is in the pre-manifest or very early manifest stages of HD. The early manifestation of HD may be impacted by the neurodegenerative effects of chronic PTSD further decreasing his level of functioning and necessitating external daily living support.

Conclusion

This case study illustrates the presentation of early changes occurring in late-onset HD. It highlights the use of a biopsychosocial model to gain a thorough understanding of the patient’s presenting issues which, in this case, were only revealed by discussion with the patient’s family. Inappropriate investigations and poor understanding of neurodegenerative conditions may have resulted in compromised patient safety. Through thorough history taking and holistic investigations, consistent with recent research, the patient’s condition was determined and treated and appropriate follow-up planned.