Catatonia in extrapontine myelinolysis: A case report and review of the literature

A complex neuropsychiatric syndrome, catatonia, is characterized by various speech, motor, and behavioral abnormalities, with bipolar affective disorder comprising the largest subgroup of patients with catatonia.[1] A usual complication of overzealous and rapid correction of electrolyte imbalances, osmotic demyelination syndrome (ODS) is classified as central pontine myelinolysis and extrapontine myelinolysis (EPM) based on the region involved. This report describes a case of catatonia secondary to ODS and provides a comprehensive literature review to describe the clinical presentation and treatment outcomes. A 38-year-old man on treatment for bipolar affective disorder for 15 years presented to the psychiatrist with generalized body stiffness and slowness, preceded by recurrent vomiting 1 month ago for 1 week, associated with dysphagia, incontinence, and dysarthria with limb posturing and withdrawal. On examination, mutism, immobility, rigidity, negativism, staring, and drooling of saliva were noted. He had waxy flexibility and automatic obedience, consistent with catatonia. There was no tremor. A review of earlier hospital records revealed a rapid correction of sodium (12 milliequivalents over 24 hours). Magnetic resonance imaging revealed T2 fluid-attenuated inversion recovery hyperintensities involving the bilateral caudate, putamen, and external capsules with diffusion restriction, suggestive of EPM [Figure 1]. Levodopa-Carbidopa was titrated up to 400 mg/day with rehabilitation, leading to complete improvement.Figure 1:: (a) T2 fluid-attenuated inversion recovery hyperintensity involving the bilateral caudate, putamen, and external capsule. (b) The same regions show abnormality on diffusion-weighted imagingI conducted a literature search of the PubMed Database with the key words "(Catatonia) AND [(Extrapontine Myelinolysis) OR (Central Pontine Myelinolysis) OR (Osmotic Demyelination Syndrome)]" and eight cases of EPM with catatonia were identified. The median time of recovery for the catatonia was five months.[2-7] Two cases were excluded due to lack of individual patient data [Table 1].Table 1: Review of the cases with catatonia in osmotic demyelination syndromeEPM can involve the caudate, putamen, cerebellum, thalami, frontotemporal cortex, and subcortical white matter. Parkinsonism, chorea, dystonia, tremor, and corticobasal syndromes have been reported in ODS.[8] Catatonia can manifest either as a brief episode, followed by Parkinsonism, or 2 weeks after, following the resolution of quadriplegia.[3-6] My patient fulfilled the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition criteria of catatonia with the presence of five out of 12 signs required for diagnosing catatonia.[1] The absence of cogwheeling and tremor differentiated catatonic rigidity from parkinsonian rigidity. Akin to previous reports, positive signs of waxy flexibility, withdrawal, negativity, and automatic obedience suggest catatonia as the clinical phenomenology, being typically absent in parkinsonism.[1] Single-photon emission tomography with iodine-123-iomazenil has demonstrated a correlation between motor and affective symptoms in catatonia with reduced GABA-A binding in the frontal, parietal, and motor cortical regions and dysfunction of the frontal-striatal-thalamic tract, reinforcing the GABA hypothesis for catatonia.[1,7] Since majority of the projection neurons of the basal ganglia are GABAergic, reduced GABA binding in the frontal-striatal-thalamic tract could lead to clinical overlap of catatonia with parkinsonism, as noted previously. Furthermore, functional imaging in EPM suggests a reduction in the presynaptic striatal dopamine transporters in addition to the local osmotic damage affecting the postsynaptic receptors, with clinical improvement using dopaminergic therapy,[8] similar to my patient. Catatonia can be dominant in EPM, the diagnosis of which should not be delayed in the background of confounding psychiatric comorbidity. Levodopa therapy can lead to complete recovery. Acknowledgement Dr. Adesh Kumar Agrawal, Assistant Professor, Department of Psychiatry, AIIMS Deoghar. Author contribution SJ was involved in the conception, execution, design and writing of the manuscript. Ethical compliance statement All authors comply with the journal's publishing ethics and guidelines. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.