Neuroacanthocytosis masquerading as psychiatric illness

Dear Editor, Neuroacanthocytosis refers to a group of inherited genetic neurological disorders characterised primarily by the presence of movement disorders and acanthocytes on peripheral blood smear.[1] Each neuroacanthocytosis syndrome is exceedingly rare. Psychiatric comorbidities involving progressive behavioural changes resembling frontal lobe syndrome, depression, anxiety, agitation, emotional instability, personality changes, obsessive-compulsive disorder and cognitive impairments have been described in the literature.[2,3] Pathology in the basal ganglia accounts for the characteristic motor symptoms, such as chorea or dystonia, and may also account for the elevated rates of psychiatric illnesses in these syndromes. Here we present a patient who presented with psychotic symptoms initially, and on further follow-up developed a movement disorder and was diagnosed with choreoacanthocytosis. A 25-year-old female, unmarried graduate, presented with an illness of 4 years, insidious in onset, with a progressive deteriorating course characterised by irritability, spitting behaviour, decreased attention, increased energy, overfamiliarity, disorganised behaviour, making grunting noises and clicking noises and decreased sleep. She was diagnosed with Psychosis unspecified and treated with Aripiprazole up to 15 mg, which led to 40% improvement. This was followed by an episode of post psychotic depression for which fluoxetine 20 mg was added. Her behavioural symptoms, like stubbornness, impulsivity, irritability, hitting herself and spitting behaviour persisted. She would not help with household chores, unlike her usual self. Despite being on regular treatment, over the next two years, the clicking noises further increased, and she developed dysphagia, psychomotor retardation, gait difficulties, head banging, slurred speech, perseveration and choreiform movements. No orolingual dystonias or tongue protrusions were noted. No family history of any psychiatric or neurological illness was present. Neurological examination showed choreiform movements in both upper and lower limbs and diminished reflexes, with the inability to perform complex motor tasks due to chorea. Lobar function testing showed poor executive functions. On neuroimaging, she had atrophy of the bilateral caudate nuclei and ventricular dilatation [Figure 1], acanthocytes on peripheral blood smear, and screened vps13A gene positive on genetic testing. Thus, the patient was diagnosed with choreo-acanthocytosis with hyperkinetic movement disorder and Personality and Behavioural disorders due to brain disease, damage and dysfunction (F07-ICD 10). She was prescribed quetiapine 275mg, sodium valproate 800mg, gabapentin 600 mg, sertraline 25 mg, tetrabenazine 75mg, clonazepam 3 mg and melatonin 6 mg in divided doses. Treatment resulted in 20% improvement. Physiotherapy was initiated.Figure 1: T1-weighted images showing volume loss and ventricular dilatation. Arrows indicating caudate atrophyNeuroacanthocytosis is a progressive disease. Neuropsychiatric disturbances appear to arise when the normal functions of the striatum are disturbed. The incidence of psychiatric symptoms in the early part of the illness is uncommon but is associated with a poorer prognosis.[4] Our patient presented with an episode of psychosis followed by a depressive episode. Personality deterioration, along with marked socio-occupational dysfunction, was also noted. The movement disorder developed over the next two years, which led to investigations that confirmed the final diagnosis. The case highlights the importance of a simple peripheral blood smear in the confirmation of the diagnosis. At present, no treatment is available to prevent or slow the progression of the disease. Treatment is symptomatic and supportive, with the aim of improving the quality of life. Authors’ contributions Concept, design, definition of intellectual content, literature search: SJ. Data acquisition AT. Manuscript preparation: SJ, AT. Manuscript editing and review: SJ, RS. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.