Published online: 2019-09-26

Letters to Editor

Prasad Krishnan, Rohit Mishra, Manaranjan Jena A 19‑year‑old male presented with complaints of acute Department of Neurosurgery, National Neurosciences Centre, onset abnormal, episodic intermittent involuntary Kolkata, West Bengal, India jerky movement of all four limbs, trunk and eye lids without loss of consciousness from 12 days. These Address for correspondence: Dr. Prasad Krishnan, movements used to subside during sleep and not Flat 3B, 9 Southend Park, Kolkata ‑ 700 029, West Bengal, India. exacerbated by visual, auditory or tactile stimulus. E‑mail: [email protected] There was positive history of difficulty in walking References with swaying on either side and slurring of speech from last 10 days. On general examination he had gum 1. Rambarki O, Rajesh A. Dreaded complications of mistaken hypertrophy [Figure 1] but no evidence of skin rash. identity‑Hygroma vs effusion following decompressive craniotomy. Neurological examination revealed abnormal chaotic J Neurosci Rural Pract 2014;5:305‑7. multidirectional movement of eyes suggestive of 2. Stiver SI. Complications of decompressive craniectomy for traumatic brain injury. Neurosurg Focus 2009;26:E7. opsoclonus with evidence of myoclonic jerks involving 3. Aarabi B, Chesler D, Maulucci C, Blacklock T, Alexander M. Dynamics of all four limbs, face and eyelids [Videos 1 and 2]. He subdural hygroma following decompressive craniectomy: A comparative had severe trunk as well as gait ataxia, incoordination study. Neurosurg Focus 2009;26:E8. and dysmetria. Rest of neurological examination was 4. Waziri A, Fusco D, Mayer SA, McKhann GM 2nd, Connolly ES Jr. Postoperative hydrocephalus in patients undergoing decompressive normal. hemicraniectomy for ischemic or hemorrhagic stroke. Neurosurgery 2007;61:489‑93. He had past history of tuberculous meningitis, 5. Park CK, Choi KH, Kim MC, Kang JK, Choi CR. Spontaneous evolution of posttraumatic subdural hygroma into chronic subdural haematoma. hydrocephalus, and generalized tonic clonic seizures Acta Neurochir (Wien) 1994;127:41‑7. since the age of two and half years. He was treated with 6. Feng JF, Jiang JY, Bao YH, Liang YM, Pan YH. Traumatic subdural complete course of antitubercular therapy along with effusion evolves into chronic subdural hematoma: Two stages of the ventriculo‑peritoneal shunt for hydrocephalus. His same inflammatory reaction? Med Hypotheses 2008;70:1147‑9. phenytoin dose was increased from 300 to 500 mg/d 1 month back due to one episode of GTCS and Tab Access this article online Levetiracetam 500 mg BD was added recently for Quick Response Code: myoclonic jerks but there was no improvement in his Website: www.ruralneuropractice.com symptoms. A clinical diagnosis of OMS with ataxia (gait, truncal as well as appendicular) was considered.

DOI: 10.4103/0976-3147.145246 Hematological, biochemical and cerebro spinal fluid examinations were normal. CSF was negative for Herpes simplex virus (HSV), Japanese encephalitis, measles and varicella zoster as well as Cryptococcus neoformas, and Mycobacterium tuberculosis. The immunological study for Dengue, rubella, HIV, Mycoplasma pneumoniae, Rickettsia, HCV, HBV, Ebstein‑Barre virus, Opsoclonus – Myoclonus poststreptococcal infection and coxsackie infection syndrome induced by phenytoin intoxication

Sir, Phenytoin is an antiepileptic drug that continues to be used widely for treatment of focal and generalized tonic‑clonic seizures. Phenytoin has narrow therapeutic window. Therefore, even a minor increase in dose leads to toxicity. Opsoclonus and myoclonus both are adverse effect of phenytoin[1] but opsoclonus– myoclonus syndrome (OMS) as a consequent effect of phenytoin toxicity is not previously reported in the literature. Figure 1: Photograph of the oral cavity showing gum hypertrophy

Journal of Neurosciences in Rural Practice | 2014 | Vol 5 | Supplement 1 S109 Letters to Editor was negative. Brain magnetic resonance imaging with evidence of significant raised phenytoin level revealed no abnormality. Electroencephalography was suggests that OMS was attributed to phenytoin toxicity. normal. Ultrasonography of abdomen and chest X‑ray Although phenytoin and carbamazepine are known was normal. Serum phenytoin level was markedly to aggravate myoclonic jerks in most of myoclonic increased (>40 µg/ml). Phenytoin was stopped and epilepsies but phenytoin toxicity presenting as OMS had levetiracetam 500 mg bd and clonazepam 0.5 mg tds not reported till date. was started. All his symptoms including opsoclonus– myoclonus were gradually disappeared over next Rajesh Verma, Sanjeev Kumar, Sumant Biyani, 15 days. Therefore, phenytoin‑induced opsoclonus– Anurag Singh myoclonus ataxia syndrome was the final diagnosis. Department of Neurology, King George Medical University, Lucknow, The repeat estimation of serum phenytoin level was Uttar Pradesh, India within normal limits. The patient became seizure free at follow‑up at 3 months. Address for correspondence: Prof. Rajesh Verma, Department of Neurology, King George Medical University, Phenytoin side effects are ataxia, nystagmus, slurred Lucknow, Uttar Pradesh, India. speech, decreased coordination, dysarthria, diplopia, E‑mail: [email protected] choreoathetosis, orofacial dyskinesias and mental confusion.[2] Other uncommon side effects like References ophthalmoplegia, seizure and encephalopathy (lethargy, 1. Dehaena I, Van Vleymen B. Opsoclonus induced by phenytoin and delirium, psychosis, stupor or coma) may be seen, diazepam. Ann Neurol 1987;21:216. especially when serum phenytoin level >40 µg/ml.[3] 2. Bruni J. Phenytoin: Toxicity. In: Levy RH, Mattson RH, Meldrum BS, th Chronic use of phenytoin medication is associated editors: Antiepileptic Drugs. 4 ed. New York: Raven Press; 1995. p. 345‑50. with persistent cerebellar dysfunction and atrophy of 3. Spector RH, Davidoff RA, Schwartzman RJ. Phenytoin‑induced cerebellar vermis along with loss of Purkinje cells.[4] ophthalmoplegia. Neurology 1976;26:1031‑4. 4. Ney GC, Lantos G, Barr WB, Schaul N. Cerebellar atrophy in patients with OMS is a rare neurological disorder and is also known as long‑term phenytoin exposure and epilepsy. Arch Neurol 1994;51:767‑71. 5. Baets J, Pals P, Bergmanse B, Foncke E, Smets K, Hauman H, et al. the “dancing eye‑dancing feet syndrome.” Opsoclonus Opsoclonus‑myoclonus syndrome: A clinicopathological confrontation. is defined as the occurrence of involuntary, repetitive Acta Neurol Belg 2006;106:142‑6. rapid conjugate ocular saccades that are irregular in 6. Klaas JP, Ahlskog JE, Pittock SJ, Matsumoto JY, Aksamit AJ, Bartleson JD, et al. Adult‑onset opsoclonus‑myoclonus syndrome. Arch amplitude and frequency, occur in all directions without Neurol 2012;69:1598‑607. an intersaccadic interval. Myoclonus occurs in most of OMS cases. OMS may be associated with ataxia, tremor, Video Available on: www.ruralneuropractice.com dysarthria and psychiatric symptoms.

OMS is more common in children. The most common Access this article online cause of OMS in children is paraneoplastic, especially Quick Response Code: Website: due to neuroblastoma, parainfectious and congenital. www.ruralneuropractice.com The exact pathophysiology of OMS is not known. Baets et al.[5] had demonstrated loss of cerebellar purkinje and granular cell layer in autopsy of OMS of paraneoplastic DOI: 10.4103/0976-3147.145254 origin.

Since OMS is a rare disease, so there are no guidelines regarding its management? In children with neuroblastoma, it usually resolves with adrenocorticotropic hormone (ACTH), or corticosteroid. There are reports in which clonazepam, baclofen, Commentary valproate had provided significant symptomatic relief to these patients.[6] The opsoclonus–myoclonus syndrome (OMS) is In our patient there was history of appearance of OMS a pluriethiological neurological disorder, seldom after recent increment of dose of phenytoin and initially encountered in the medical practice, affecting 1 in his symptoms were unresponsive to levetiracetam. There 10 000 000 people annually, producing about 60 infections was significant response and complete resolution after worldwide every year. In children, the most frequent withdrawal of phenytoin and addition of clonazepam cause of OMS is the neuroblastoma, in more than 50% S110 Journal of Neurosciences in Rural Practice | 2014 | Vol 5 | Supplement 1