Dynamic posturography findings in central nervous system disorders.

Dynamic posturography provides functional, selective testing of three sensory modalities for maintenance of balance: vestibular, visual, and somatosensory. Sensory receptors in vertical semicircular canals and utricles, via the vestibulospinal tract, mediate a disconjugate response to the legs, enabling synchronized reciprocal stabilization of the body for control of motion. The patient is systematically exposed to different combinations of useful and conflicting visual, vestibular, and support surface input. The effect of each on stability is appraised. Early posturography reports dealt primarily with sensory organization test (SOT) results. Improved software for movement coordination (MC) tests offer greater identification of problems involving the central nervous system. One hundred fifty-one patients were studied over a 9-month period. Central disorders were present in 31 cases (20.5%) and 90.3% of these were abnormal in sensory organization tests (SOTs). Abnormal movement coordination (MC) results occurred in 80.6% of central nervous system (CNS) disorders. SOTs 4, 5, and 6 in combination were abnormal in 35.5%, and 70% of these cases were also abnormal in MC responses. False-positive responses occurred in less than 4% of cases. Posturography offers a significantly high detection rate in CNS disorders causing dysequilibrium. Long loop latency reflexes, as they relate to maintenance of balance, appear important in the pathophysiology of abnormal SOT and MC responses.

The role of dynamic posturography in neurotologic diagnosis.

Electronystagmography and rotary vestibular testing are of definite but limited value in screening the dizzy patient. Objective identification of a vestibular abnormality is valuable, but there is an additional need to appraise the functional capacity of those suffering central or peripheral disorders causing spatial disorientation or disequilibrium. Records of 175 patients undergoing posturography in the author's practice over a 1-year period were reviewed. Diagnosis was established by conventional neurotologic means including computerized electronystag-mography. Abnormal results on posturography were identified by criteria established through the national users group of Equi-Test participants. There were 112 peripheral cases with 50 (45%) abnormal on posturography, in contrast to 53 central patients with 38 (72%) abnormal. Posturography established a functional level of balance in certain peripheral and central disorders and provides limited but significant aid to assist in distinguishing between the two.

Virtues and vagaries of high-resolution CT air cisternography in the diagnosis of acoustic neuromas.

A series of 125 consecutive, bilateral, high-resolution, computerized tomographic (CT) air cisternograms was prospectively reviewed and analyzed. Emphasis was placed on identifying problems encountered in performing the study and potential sources of error in interpretation. In two patients there was difficulty in transporting the air bolus because spinal cord tumors coexisted with bilateral acoustic neuromas. Potential false-positive results were avoided in four patients by persistent efforts to fill the internal auditory canal. Later reexaminations were recommended for four patients whose examinations were suspicious or suggestive of tiny acoustic neuromas. Unilateral Mondini malformation was incidentally diagnosed in one patient. Six patients required therapy for persistent headache after lumbar puncture. High-resolution CT air cisternography is believed to be the method of choice for investigating the nonenhancing or small acoustic neuroma. However, this method is not without potential problems, some of which are discussed.

Cholesteatomas of the temporal bone: role of computed tomography.

Computed tomography (CT) of the temporal bone was performed in 64 patients thought to have a cholesteatoma of the middle ear. Twenty had not had surgery before, while 44 had been operated on; special consideration was given to 21 patients who were scanned immediately before a second operation and had confirmation of the CT findings. Inflammatory disease without cholesteatoma was characterized by absence of erosion of the otic capsule or ossicular chain. Sharply circumscribed cholesteatomas were easily diagnosed by CT. When they were combined with scarring, granulation tissue, or postsurgical changes, the resulting soft-tissue masses were indistinguishable, although cholesteatoma may be suspected if there is evidence of progressive bone erosion about the middle ear. CT can play a major role in postoperative follow-up by confirming that the ear is normal and demonstrating displacement of ossicular grafts or prostheses.

High resolution CT scanning for detection of cholesteatoma and complications in the postoperative ear.

Otologists who prefer intact canal wall surgery for removal of cholesteatoma recognize a 12.25% return rate. Revisions often indicated to correct hearing loss are frequently negative for recurrent cholesteatoma. To determine the reliabiity of a noninvasive method of diagnosing recurrent disease and possible complications, 40 patients previously operated on for cholesteatoma using the intact canal wall technique were scanned with a General Electric 8800 scanner. Second procedures were performed on 24 patients and findings compared with preoperative film interpretations. Scans correctly predicted no significant masses in 6 patients and cholesteatoma recurrence in 11; the remaining 6 with diffuse soft tissue changes were incorrectly diagnosed. Focal areas of bone erosion were detectable in 3 cases, indicating active or potential complications. Scans were reliable in detecting cholesteatoma depending upon the pathology.

The vascular anatomy of the eustachian tube in the guinea pig.

Vascular anatomy of the eustachian tube has received little attention in the world's medical literature. Forty guinea pigs were perfused with Berlin Blue as a contrast medium and the eustachian tube microvascular architecture visualized through surface preparations. A diffuse, dense two-layered capillary network was found which followed the distribution of mucous glands. Five animals suffering from suppurative otitis media showed marked capillary congestion with increased vessel to tissue density. Relationships to gross arterial and venous supply as found in the human are discussed.