Literature Review: A Roundup of Important Recent Studies

Bottom line: Children with UHL demonstrated improvement in language scores and verbal IQ over time but not in test scores or school performance.

Reference: Lieu JEC, Tye-Murray N, Fu Q. Longitudinal study of children with unilateral hearing loss. Laryngoscope. 2012;122(9):2088-2095.

—Reviewed by Sue Pondrom

Vitamin A Not an Effective Treatment for Olfactory Disorders

Is vitamin A an effective treatment for post-infectious and post-traumatic smell disorders?

Background: Olfactory dysfunction, involving a decreased or absent sense of smell, has been associated with diseases such as viral infections of the upper respiratory tract, chronic rhinosinusitis and head injuries. Only a few studies have looked at the use of prednisolone or intensive stimulation of the olfactory system as treatments. Vitamin A was chosen for this study for its potential to stimulate regeneration and repair of the peripheral olfactory system.

Study design: Double-blind, randomized, placebo-controlled clinical trial.

Setting: Department of Otorhinolaryngology, University of Dresden Medical School, Germany.

Synopsis: In 52 patients ages 20 to 70, the authors utilized the Sniffin’ Sticks test kit to measure odor thresholds, odor discrimination and odor identification (TDI scores). Vitamin A was prescribed at a dose of 10,000 for three months and follow-up testing was performed, on average, five months after the first investigation. Overall, 44 percent of all patients reported an improvement in olfactory function. There was no significant difference between placebo and vitamin A groups in TDI scores. Etiology (post-infectious or post-traumatic) had no influence on the TDI change between groups. The authors noted that a previous study by Duncan and Briggs showed an improvement in olfactory function, with dosages at 50,000 to 150,000 IU per day. The authors of this study said they could not rule out that a higher dosage of vitamin A may have a beneficial effect, but they worried about the possible side effects.

Bottom line: The applied dosage and duration of vitamin A in this study cannot be recommended in the treatment of post-infectious and post-traumatic olfactory dysfunction.

Reference: Reden J, Lill K, Zahnert T, Haehner A, Hummel T. Olfactory function in patients with postinfectious and posttraumatic smell disorders before and after treatment with vitamin A: a double-blind, placebo-controlled, randomized clinical trial. Laryngoscope. 2012;122(9):1906-1909.

—Reviewed by Sue Pondrom

ECD as Alternative Surgery for Benign Parotid Tumors

Is extracapsular dissection (ECD) an option for the resection of certain benign parotid tumors, and what are the complication rates and effectiveness of ECD versus superficial parotidectomy (SP)?

Background: ECD differs from classic enucleation, which involves the incision and shelling out of the contents of the tumor capsule. In ECD, the dense parotid fascia overlying the tumor is sharply incised followed by a blunt dissection to the level of the tumor. Under magnified visualization, a loose areolar plane may be seen 2 to 3 mm adjacent to the tumor and is the preferred plane of dissection. Careful dissection continues along the tumor capsule to prevent rupture of the small outpouchings of the tumor that may be encountered. Superficial and/or partial parotidectomy is the gold standard treatment of solitary, benign parotid tumors. SP, with special attention to the removal of the capsule to cure pleomorphic adenomas, is frequently the treatment of choice; ECD is now offered as an alternative method to