A 25-year-old man with history of cocaine use presented to the emergency room with left-sided upper and lower limb weakness as well as sensory impairment involving the face. Symptoms evolved such that he was bed-ridden after 48 h. He had no history of previous neurological or systemic symptoms. Computed tomography (CT) of the brain showed bilateral periventricular hypodensities. CT angiography of cervical and intracranial vessels was unremarkable. An MRI study of the brain demonstrated increased FLAIR signal deep in the right and left hemispheres (Fig. ), which also displayed patchy gadolinium enhancement (Fig. ) and restricted diffusion (Fig. –). Five days after admission he developed swallowing difficulty, dysarthria, and confusion. In addition to the previously noted MRI abnormalities, repeat imaging showed new lesions in the left internal and external capsules, putamen and corona radiata, right medial pons and left cerebellar peduncle, with heterogenous gadolinium enhancement (Fig. –). The neuroradiological impression was that the lesions were most compatible with demyelinating disease. A urine screen was positive for cocaine, cannabinoids, and oxycodone, and negative for amphetamine, methadone, benzodiazepines, and barbiturates. Other investigations included the following normal or negative results: complete blood count, serum electrolytes, urea, creatinine, glucose, erythrocyte sedimentation rate, antinuclear antibodies, rheumatoid factor, perinuclear and cytoplasmic anti-neutrophil cytoplasmic antibodies (pANCA and cANCA respectively), extractable nuclear antigens, lupus inhibitor, C3, C4, CH50, urinalysis, vitamin B12, angiotensin converting enzyme level, thyroid stimulating hormone level, free T3 and T4, cortisol level, lipid profile, very long chain fatty acids, viral serology for HIV, CMV, Hepatitis A, B, and C, Lyme serology, syphilis screen, blood screen for salicylate, acetaminophen, and ethanol. Liver enzymes (AST, ALT and GGT) were mild to moderately elevated and subsequently normalized over a period of six months. Cerebrospinal fluid (CSF) results included: slightly elevated protein at 0.50 g/l (normal 0.20–0.40 g/l), normal glucose and chloride, normal total cell count (3 × 106/l), negative oligoclonal bands, normal IgG index, elevated albumin index at 9.0 (2.7–4.7), negative cryptoccocal antigen, negative cultures for bacteria and fungi, negative polymerase chain reaction (PCR) studies for CMV and HSV 1–2, and normal cytology.\nHe was treated with intravenous methylprednisolone, 1000 mg daily for five consecutive days, and subsequently underwent plasma exchange. During plasma exchange his neurological condition stabilized and he subsequently achieved good, albeit partial, recovery. At three months follow-up he had mild residual left-sided hemiplegia but was otherwise independent in activities of daily living and starting to return to work. Follow up MRI five months after presentation showed reduction in the size of lesions, no enhancement, and no new lesions (Fig. –). MRI 21 months after the initial presentation also showed no new lesions (not shown).
A 57-year-old man with substance abuse disorder was brought by his family to the emergency room because of strange behavior. Five days prior to admission, he fell off his bicycle and came home with a scalp laceration on the left side of the head. Since then, his family noticed him acting oddly. He was seen walking back and forth in the house between the front door and the back door. He emptied the ice tray and he poured sugar into a shopping bag for no reason. He could no longer perform habitual tasks, such as cooking. His family described his gait as slow “like a zombie.” It was also unusual for him not to leave the house 5 days in a row. He does not see a primary care physician. According to his family, he smoked tobacco regularly (2 packs/day for 40 years), consumed alcohol rarely, and abused marijuana and cocaine.\nThe patient did not complain of headache, nausea, dizziness, and so on; he thinks nothing is wrong with him. Blood pressure was 187/104 mm Hg, heart rate 77 beats/min, respiratory rate 16 breaths/min, temperature 36.6°C, and blood oxygen saturation 100%. Criteria for hypertensive emergency or urgency were not met. He was awake and alert with normal thought content and intact ability to answer questions, but his affect was flat, he was indifferent to his condition, and he exhibited psychomotor retardation. On neurological examination, he was oriented to self, place, and immediate situation, but was oblivious of the month, day, and year. His ability to concentrate was mildly impaired and he pauses frequently when speaking; nevertheless, speech and language function were intact. Cranial nerve functions and motor strength were all normal. Deep tendon reflexes were brisk (3+) in all extremities. Ankle clonus and Babinski sign were absent. Cerebellar signs were also absent. Head computed tomography showed mild diffuse brain atrophy. Blood counts and chemistry were all normal except for mild hyperammonemia (39 µmol/L).\nHe was admitted to the neurology service. Urine was positive for cocaine and benzodiazepine, but only cocaine was found significant on quantitative analysis (levamisole was not tested). Additional studies, including thyroid stimulating hormone; folate; B12; HgbA1C; HIV; hepatitis panel; heavy metal screen for lead, arsenic, and mercury; and blood toxicology for ethanol, methanol, salicylates, acetaminophen, and so on, were all negative. Brain MRI revealed diffuse confluent subcortical white matter hyperintensities on T2-FLAIR and diffusion-weighted imaging (DWI) with low-apparent diffusion coefficient (ADC) in some areas (restricted diffusion) and high ADC in other areas (T2 shine-through effect). The cerebral cortex, cerebellum, basal ganglia, thalamus, and brainstem were all normal (). EEG showed mild diffuse slowing with inordinate amounts of theta waves intermixed with low-voltage beta and alpha activity (). Lumbar puncture was considered but not pursued because we were convinced that he has cocaine-induced TL and we could not justify exposing him to the risk of brain herniation. Albeit infrequent, brain herniation may occur with diffuse brain edema (eg, liver failure).\nImmunosuppressive therapy in cocaine-induced TL has been associated with a favorable or unfavorable outcome (see “Introduction”). Notwithstanding this uncertainty, we chose to treat the patient with a 5-day course of prednisone because of the extent of his disease. Prednisone 60-mg qd was administered on hospital day 4, tapered to 20 mg qd over 5 days, and stopped on hospital day 9. Nutritional therapy and assistance with activities of daily living resulted in gradual normalization of mental status and behavior. After 3 weeks in acute care, the patient was discharged to a rehabilitation facility. He missed his appointments and was seen again in clinic after 5 months. His family pointed out that his cognitive function returned to normal 2 weeks after he was discharged from acute care and at that point he started engaging again in the activities of daily living. During clinic visit, he reported (and his family agreed) that he no longer takes cocaine and other drugs of abuse. Neurological examination and cognitive evaluation did not detect any abnormalities. Follow-up brain MRI showed complete absence of diffusion restriction and near-100% resolution of white matter hyperintensity (). Follow-up EEG showed normal alpha rhythm posteriorly and normal beta activity anteriorly during wakefulness ().