Subannular tube insertion: anatomical considerations.

OBJECTIVES: To assess the distance between the bony groove created during subannular tubes placement and the chorda tympani, and examine the depth of the hypotympanum and retrotympanum. METHOD: Grooves drilled in cadaver temporal bones at two levels were imaged to measure: the distance between the chorda tympani nerve and the tympanic sulcus, and the depth of the hypotympanum and the retrotympanum relative to the annulus. RESULTS: The chorda tympani was between 0 and 5 mm from the groove cut across the annulus. The hypotympanum average depth was 2 mm (0.44-6.40 mm) and the retrotympanum average depth was 1 mm (0-2.53 mm). CONCLUSION: Grooves drilled across the tympanic sulcus should be placed at a point 20 per cent of the height of the tympanic membrane or lower; this will ensure least risk of injury to the chorda tympani nerve. The depth of the hypotympanum and retrotympanum dictates that the posteroinferior part of a subannular tube flange should be approximately 2 × 1 mm.

Familial colloid cyst.

Colloid cysts of the third ventricle are rare benign tumours that can present as symptomatic hydrocephalus or be an incidental finding on imaging. This report presents familial colloid cysts found in a mother and daughter. Prior examples of familial colloid cysts are also reviewed and suggestions regarding the mode of inheritance and screening strategy are proposed.

Comparative outcomes of ulnar nerve transposition versus neurolysis in patients with entrapment neuropathy at the cubital tunnel: a 20-year analysis.

BACKGROUND: Entrapment neuropathy of the ulnar nerve at the level of the elbow is the shared domain of multiple surgical specialties. A wide variety of operative methods for its surgical management have been reported. Our hospital utilizes neurolysis (NL) and subcutaneous transposition (AST). The aim of this paper was to compare the clinical outcomes in patients treated by ulnar nerve transposition versus neurolysis over a 20-year period. METHODS: We included patients who underwent either neurolysis or an ulnar nerve transposition. A retrospective analysis was performed which included 480 patients at our institution between January 1992 and December 2012. In total, physical and electronic records for 480 patients were reviewed. Three-hundred and one underwent ulnar nerve transposition and 179 underwent ulnar nerve neurolysis . RESULTS: In the AST group 201/301 patients suffered from parasthesiae pre-operatively and 156/301 had pain at and around the cubital tunnel. Paresis of the ulnar nerve innervated muscles was present in 99/301 patients. At the 3-month follow-up appointment, 187/201 patients with parasthesiae and 113/156 patients with local pain had resolution of their symptoms. In the NL group 151/179 patients had parasthesiae pre-operatively and 126/179 had pain at and around the cubital tunnel. Paresis of the ulnar nerve innervated muscles was present in 56/179 patients. At the 3-month follow-up appointment, 141/151 patients with parasthesiae and 117/126 patients with local pain had resolution of their symptoms. CONCLUSIONS: In cases of ulnar nerve compression at the cubital tunnel, both neurolysis and transposition are effective in improving clinical outcome. The only statistically significant advantage of neurolysis over transposition seems to be relief of localized elbow pain. We recommend neurolysis as the preferred procedure.

Reductive N,N-dimethylation of amino acid and peptide derivatives using methanol as the carbonyl source.

Formaldehyde is readily formed from methanol in the presence of palladium-on-charcoal and air. The use of this methanolic formaldehyde solution for the reductive methylation of amino groups in amino acid and peptide derivatives by catalytic hydrogenation has been studied and found to be superior to the use of aqueous formaldehyde because no contaminating paraformaldehyde is present. Some data on N-isopropylation are given.