The effect of a therapeutic lithium level on a stroke-related cerebellar tremor.

Lithium is a mood stabiliser used in the treatment of acute mania, bipolar disorder and as augmentation for unipolar major depression. Tremor is a common adverse effect associated with lithium at both therapeutic and toxic serum levels. We present a case of dose-dependent changes in the quality and intensity of a stroke-related, chronic cerebellar tremor with lithium treatment at serum levels within the therapeutic range. On admission, the patient in this case had a baseline fine, postural tremor, which increased in frequency and evolved to include myoclonic jerks once lithium therapy was initiated. Although the patient's serum lithium level was never in the toxic range, his tremor returned to baseline on reduction of his serum lithium level. This case highlights that a pre-existing, baseline tremor may lower the threshold for developing myoclonus. It also suggests that caution may be warranted with lithium therapy in the setting of known cerebellar disease.

A case of granuloma annulare mimicking tinea cruris.

Granuloma annulare (GA) is a benign, self-limited skin disease of unknown etiology characterized by annular, flesh-colored to erythematous grouped papules or plaques. Lesions of GA are typically located on the lateral or dorsal surfaces of the hands and feet, arms, thighs, and trunk. We present the case of a patient with GA who presented with erythematous, annular plaques localized to the bilateral inguinal folds, mimicking tinea cruris. On clinical examination, the lesions were thought to be tinea cruris. A subsequent punch biopsy revealed the lesions to be granuloma annulare. This case highlights an unusual location where GA can first present in a patient. It also suggests that GA should be considered among the differential diagnoses along with tinea cruris, when evaluating localized annular lesions of the groin.