Anatomy,physiology, and pathophysiology of the pedunculopontine nucleus

The pedunculopontine nucleus is composed of cholinergic and non‐cholinergic neurones and is located in the caudal pontomesencephalic tegmentum. Evidence suggests that the nucleus plays a role in the production and control of movement. The nucleus has dense interconnections with the basal ganglia, as well as with other areas of the brain associated with motor control. Electrical stimulation of the pedunculopontine nucleus in the decerebrate cat or rat produces organized locomotor movements. Physiological studies show that the pedunculopontine nucleus modulates its activity in response to locomotion, as well as voluntary arm and eye movements. Degeneration of the pedunculopontine nucleus is seen in post‐mortem brains in humans with Parkinson's disease and Parkinsonian syndromes. In animal models of Parkinson's disease, metabolic changes are seen in the pedunculopontine nucleus, and chemical inhibition or mechanical disruption of the nucleus can produce an akinetic state in animals and man. In this paper we review the literature in support of the suggestion that some of the symptoms of Parkinson's disease are caused by dysfunction of the pedunculopontine nucleus. In accordance with this view, direct stimulation of the nucleus can ameliorate some symptoms of the disease, as demonstrated in both experimental animals and man. © 2008 Movement Disorder Society     

Peduncular hallucinosis secondary to central pontine myelinolysis

Peduncular hallucinations are generally associated with lesions in the midbrain. They have rarely been associated with central pontine myelinolysis, a condition associated with rapid alterations in serum sodium and chronic alcoholism. Described herein is the case of a 46‐year‐old man who developed typical peduncular hallucinations, whose imaging demonstrated central pontine myelinolysis. After alcohol cessation and neuroimaging resolution, the patient's hallucinatory phenomena abated.     

Topical clindamycin versus systemic tetracycline in the treatment of hidradenitis suppurativa

Background: Antibiotics are often used to treat hidradenitis, but only topical clindamycin has been shown to be effective in a randomized controlled trial. The paucity of these trials may be the result of difficulties in disease assessment. Objective: We compare topical clindamycin with systemic tetracycline in the treatment of hidradenitis suppurativa, and study clinical disease assessment. Methods: A total of 46 patients with stage 1 or 2 hidradenitis suppurativa were treated in a double-blind, double dummy controlled trial. Results: No significant difference was found between the two types of treatment. Patients’ global assessment of disease was significantly worse than physician’s assessment in 3 of 5 evaluations (P = .0096 to .015), but the correlation between patients’ and physicians’ assessments was satisfactory after only one visit (rs = .761 to .895). Soreness was the key factor in patients’ overall assessment of the disease. Conclusion: Systemic therapy with tetracyclines did not show better results than topical therapy with clindamycin. Subjective factors, particularly soreness, appear to be a key factor in patients’ assessment of the disease and should, therefore, be included as an outcome variable in future therapy studies. (J Am Acad Dermatol 1998;39:971-4.)