Oral psoralen and ultraviolet-A light (PUVA) treatment of psoriasis and persistent risk of nonmelanoma skin cancer. PUVA Follow-up Study.

BACKGROUND/METHODS: The treatment of psoriasis with high-dose exposure to oral psoralen and ultraviolet-A light (i.e., PUVA) substantially increases the risk of cutaneous squamous cell cancer, but not of basal cell cancer, within a decade of beginning treatment. To assess the persistence of cancer risk among individuals treated with PUVA, including those who discontinued therapy long ago and those without substantial exposure to other carcinogens, we prospectively studied a cohort of 1380 patients with psoriasis who were first treated during the period from January 1, 1975, through October 1, 1976, and evaluated risk factors associated with the development of cutaneous squamous cell cancers and basal cell cancers after 1985. RESULTS: From 1975 through 1996, 237 patients developed 1422 cutaneous squamous cell cancers. From 1986 through 1996, 135 (12.5%) of 1081 patients without a prior squamous cell cancer developed 593 such tumors. From 1975 through 1997, 247 patients developed 1042 basal cell cancers; these patients included 151 individuals with a first basal cell cancer after 1985. Among those without a squamous cell or a basal cell cancer in the first decade of the prospective study, a strong dose-related increase in the risk of squamous cell cancer was observed in the subsequent decade (adjusted relative risk [> or =337 treatments versus <100 treatments] = 8.6; 95% confidence interval = 4.9-15.2). Risk of basal cell cancer was substantially increased only in those patients exposed to very high levels of PUVA (> or =337 treatments). CONCLUSIONS: High-dose exposure to PUVA is associated with a persistent, dose-related increase in the risk of squamous cell cancer, even among patients lacking substantial exposure to other carcinogens and among patients without substantial recent exposure to PUVA. Exposure to PUVA has far less effect on the risk of basal cell cancer. The use of PUVA for psoriasis should be weighed against the increased cancer risk.

Facial reanimation after facial nerve injury.

Patients with facial paralysis are often seen in neurosurgical practice. Obtaining full facial symmetry and function after facial nerve damage presents the neurosurgeon with a difficult challenge. Various surgical techniques have been developed to deal with this problem. These include primary nerve repair, nerve to nerve anastomosis, nerve grafting, neurovascular pedicle grafts, regional muscle transposition, microvascular muscle transfers, and nerve transfers. Patient selection, timing of surgery, and details of surgical technique are discussed. The results of hypoglossal-facial anastomosis in 24 patients are described.

The marginal mandibular nerve in rhytidectomy and liposuction surgery.

A concern in the current trend toward more aggressive undermining in rhytidectomy and liposuction surgery has been the potential for damage to the marginal mandibular nerve. This study was undertaken in an attempt to clarify the exact peripheral pathway of the marginal mandibular nerve. A series of 22 fresh cadaver heads were studied bilaterally by gross dissection and histologic studies. It was found that dissection superficial to the platysma up to a point 2 cm lateral to the lower lip can be done safely. Medial to this point, dissection is hazardous and is not indicated because the marginal mandibular nerve becomes more superficial as it travels to innervate its effector muscles. Additionally, dissection in this area is technically difficult because of the tight adherence of the skin to the underlying muscles. This adherence generally permits only the formation of fine superficial rhytids that are best treated by chemical peel or dermabrasion.

The frontalis nerve in the temporal brow lift.

Brow elevations via the indirect temporal lift approach was carried out on a series of 26 cadaver half heads. The purpose of the dissection was to identify the course and depth of plane of the frontalis branch of the facial nerve. Of particular interest was the area superolateral to the brow. Histologic sections were taken along the course of the nerve to determine its exact depth. It was determined that the nerve lay in the superficial musculoaponeurotic system layer of superficial fascia lying above the level of the temporalis fascia. Utilizing this information, a method of dissection in the temporal lift operation is described that safely avoids the frontalis branch of the facial nerve.

Inhibition of labyrinthine nystagmus by visual fixation: effects of ablation of visual cortex and superior colliculi.

A study was conducted to destroy two specific areas of the cat's visual system in order to determine if these lesions would affect the visual inhibition of calorically-induced vestibular nystagmus. The occipital visual cortex was removed in eight cats and the superior colliculi were removed bilaterally in nine cats. Postoperative vestibular testing revealed no significant change in the electronystagmography tracings and response to visual fixation. These findings suggest that, in cats, the visual inhibition of labyrinthine nystagmus is not dependent upon the integrity of the visual cortex or superior colliculi. The hypothesis is brought forward that the visual inhibition of the vestibular nystagmus is merely a reflex of the brain stem to light stimulus, mediated via the cerebellum.