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 41-year-old woman presented to the emergency room of another hospital with recent confusion and impaired balance. She had been using cocaine daily for seven months. MRI FLAIR images showed multiple white matter signal changes in both cerebral hemispheres in a predominantly periventricular distribution (Fig. –) sparing the corpus callosum, cerebellum and brainstem. Restricted diffusion was present in many lesions (not shown). Subtle gadolinium enhancement was present in a few lesions (not shown). She was treated with supportive care for one week and then discharged with partial recovery. She resumed cocaine use and was then admitted to our centre six weeks after the previous hospital discharge because of worsening neurological symptoms. She was completely bedridden with inability to walk, incontinence, severely impaired communication skills, behavioural problems, cognitive impairment, and multifocal neurological deficits. MRI FLAIR images showed marked progression compared to the previous study. Confluent white matter abnormalities involved both cerebral hemispheres (Fig. –). There was subtle scattered restricted diffusion and no gadolinium enhancement. Urine testing was positive for cocaine, oxycodone, opiates, benzodiazepines, tramadol and citalopram, and negative for cannabinoids, amphetamine and methadone. Other investigations included the following normal or negative results: complete blood count, electrolytes, glucose, liver enzymes, thyroid stimulating hormone, T3, T4, creatinine kinase, angiotensin converting enzyme, HIV, Hepatitis A, B, and C screens, Lyme serology, syphilis screen, blood screen for salicylates, acetaminophen and ethanol. The serum creatinine was elevated (137 micromoles/l) as was the urea (7.6 millimoles/l). Serum albumin was low (29 g/l). The erythrocyte sedimentation rate ranged from 22 to 64 on multiple samplings, C-reactive protein was elevated at 11 mg/l while antinuclear antibodies, pANCA, cANCA, C3, C4, NMDA receptor and anti-thyroid peroxidase antibodies were normal. The vitamin B12 level was low at 166 picomole/l (normal >180). Copper, zinc and ceruloplasmin levels were normal. CSF protein was slightly elevated at 0.48 g/l. The glucose, chloride and cell count (4 × 106/l) were normal. No CSF acid fast bacilli were seen and cultures for bacteria and fungi were negative. CSF PCR for CMV and HSV1–2 were negative. She was treated with intravenous methylprednisolone, 1000 mg/day for five days, and plasma exchange. She showed substantial, albeit partial, recovery soon thereafter which continued over the course of several months. At four months follow-up multiple domains of cognitive function were improved but she had some residual deficits in attention, calculation, and visuospatial function. She was independent with respect to walking and most activities of daily living. Follow-up MRI at that time showed improvement of the subcortical and periventricular signal abnormalities and no new lesions. Similarly, no new lesions were seen on MRI 13 months after presentation (not shown).