Increased CSF protein in chloroquine-induced axonal polyneuropathy and myopathy

Few data are available about myopathy and polyneuropathy as rare side effects of chloroquine treatment. Even more rarely are cerebrospinal fluid (CSF) abnormalities in chloroquine polyneuropathy/myopathy.

The patient is an 81-year-old woman with a 30-year history of chronic polyarthritis. As a basic therapy, she received chloroquine (250 mg per day) since 1997. Already, 1 year later she developed slowly progressive gait disturbance, which led to recurrent falls, and forced her to use crutches and other orthotic devices. Since March 2001, she was no longer able to climb stairs. Since then she also developed sensory disturbances in both lower limbs. Clinical neurological investigation revealed weakness and wasting of all four limbs and reduced tendon reflexes and stocking-type sensory disturbances. Nerve conduction studies were indicative of an axonal polyneuropathy. Electromyography was non-specifically abnormal. Muscle biopsy of the gastrocnemius muscle disclosed neuropathic and myopathic features and frequent fibers with partially rimmed vacuoles, containing concentrically or parallelly sliced inclusions. CSF investigations disclosed increased protein but otherwise normal findings. Five months after discontinuation of chloroquine and replacement by leflunomid, there was marked clinical improvement.

Chloroquine polyneuropathy/myopathy may go along with increased CSF protein. Discontinuation of the causative agent results in prompt recovery of the described abnormalities.