Table 2.

Summary of individual case reports of patients with encephalitis lethargica and tics

Study	Country	Age	Sex	Aetiology of encephalitis	Tics	Other neuropsychiatric symptoms	Additional findings	Main limitations
Russel [12]	Canada	23	F	Encephalitis lethargica	Described as ‘rhythmical tic-like contraction of the left arm drawing it up across the chest and accompanied by a sort of a kicking movement of the left leg’	Sudden onset twitching of the hands and face, ocular nystagmus, involuntary micturition (in the context of chronic parkinsonism)	N/A	Lack of immunological testing
Martino et al. [13]	N/A	‘Middle-aged’	F	Encephalitis lethargica-like variant of autoimmune basal ganglia encephalitis	Unspecified tics developed after acute encephalitic episode	Acute presentation: diplopia, headache, behavioural symptoms, hypersomnolence, followed by oculogyric crises, parkinsonism, dystonic posturing of the right arm; chronic sequelae: obsessive-compulsive behaviours, anxiety, panic attacks, dysthymia	Anti-basal ganglia antibodies and striatal changes during the acute encephalitic crisis	Description of tics lacking detail
Maranis et al. [14]	Greece	28	F	Encephalitis lethargica	Unspecified orofacial tics	Acute presentation: generalised tonic-clonic seizure with subacute expressive aphasia, anxiety, and agitation; chronic sequelae: parkinsonism, delusions, emotional lability, insomnia, and catatonia	Rapid and sustained improvement with immunotherapy	Diagnosis based on clinical features (sleep disorder, parkinsonism, and psychiatric disturbance); lack of thorough autoimmune panel
Pawela et al. [15]	Australia	5	M	Autoimmune basal ganglia encephalitis described as encephalitis lethargica	Pre-existing motor tics that worsened during the encephalitis period	Acute presentation: disinhibited behaviour, mutism, dystonia, and akinesia; chronic sequelae: anxiety and obsessive-compulsive behaviours	Positive serum dopamine-2-receptor autoantibodies	Description of premorbid neuropsychiatric state lacking detail