Differentiation can be difficult

Nervous system disease is an uncommon complication of sarcoidosis. We present the case of a man found to have extensive meningeal granulomatous inflammation, an intra-cranial mass, and concurrent pulmonary disease all attributable to sarcoidosis. This case highlights the difficulty in firmly diagnosing neurosarcoidosis and in distinguishing it from tuberculosis in some instances.

Case history

A 32 year old white man was referred to our hospital for further investigation. He had been well until three months previously, when he had collapsed to the ground with no warning or apparent loss of consciousness. He recovered immediately but suffered two similar episodes, which were witnessed, over the subsequent three months. Two months before presentation he had experienced a “rushing sensation” spreading from the neck to the head and was seen to be staring blankly into the distance with posturing of the outstretched arms for about 20 seconds. He was unresponsive to questioning. Again he made a full, immediate recovery. On another occasion he saw shortlived, strobe-like flashes of light in his left visual field. He was physically fit with no respiratory symptoms. He had no significant medical history and took no drugs. Physical examination showed no abnormality.

He had peripheral blood lymphopenia with an absolute lymphocyte count of 0.8 x 10⁹, a normal total white cell count, and normal biochemical profile including serum calcium concentration. His CD4:CD8 ratio was normal. The erythrocyte sedimentation rate was 11 mm in the first hour and the C reactive protein concentration 24 U/l. Syphilis serology gave negative results. Cerebrospinal fluid obtained by lumbar puncture had a lymphocyte count of 4 x 10⁶/l, red blood count 2 x 10⁶/l, and a greatly raised protein concentration of 2.1 g/l. Cerebrospinal fluid glucose concentration was low at 2.7 mmol/l, with a plasma glucose concentration of 5.2 …