Biomedical subjects

G Riaz

Publications and source records attributed to G Riaz.

5 recordsLinked to original sources

PubMed1993

Thermography as a diagnostic aid in sciatica.

Thermography has been proposed as a diagnostic aid in patients with sciatica. Supporters of thermography state that: (a) normal patients have normal thermograms of their lower extremities, and (b) abnormal patients (with disk ruptures causing sciatica) have abnormal thermograms. To test these two hypotheses, 56 patients with clinically documented acute sciatica, with a supporting diagnostic study [computed tomography (CT), CT/myelography, and/or magnetic resonance imaging] showing a ruptured disk, had presurgical thermograms. One year after surgical intervention, they had to have had a documented success to surgical treatment intervention to stay in the study. These 56 patients were then matched with 56 control (normal) patients who had electronic thermograms. The 112 thermograms were then interpreted blindly by two thermographers. The sensitivity and specificity of thermography as a diagnostic aid in sciatica were statistically analyzed. The sensitivity of thermography (its ability to be positive when sciatica was clinically obvious) was 60% and 50% for the two thermographic readers. The specificity of thermography (its ability to be negative in asymptomatic patients) was 45% and 48% for the two thermographers. Our conclusions are no different than those published in 1985: thermography is not useful as a diagnostic aid in sciatica.

Adult↗

PubMed1991

Variations in anatomy of the ulnar nerve at the cubital tunnel: pitfalls in the diagnosis of ulnar neuropathy at the elbow.

Two processes account for most instances of ulnar neuropathy at the elbow: compression in the retroepicondylar groove, and compression by the humeroulnar aponeurotic arcade joining the two heads of the flexor carpi ulnaris. While conventional electrodiagnostic criteria may localize an ulnar neuropathy to the elbow, separating retroepicondylar compression from humeroulnar arcade compression is more difficult. In 130 cadaver elbows, we examined the relationships between the medial epicondyle, flexor carpi ulnaris, and ulnar nerve. The humeroulnar arcade lay from 3 to 20 mm distal to the medial epicondyle, the intramuscular course of the nerve through the flexor carpi ulnaris ranged from 18 to 70 mm, and the nerve exited the flexor carpi ulnaris 28 to 69 mm distal to the medial epicondyle. In 6 specimens, dense fibrous bands bridged directly between the medial epicondyle and the olecranon proximal to the cubital tunnel proper; accessory epitrochleoanconeus muscles were present in 14 specimens: both may cause ulnar neuropathy at the elbow. Anatomical variations may contribute to the difficulty in separating causes of ulnar neuropathy at the elbow.

Cadaver↗

PubMed1990

Facial myokymia in syringobulbia.

A patient with a 2-year history of progressive ataxia and tingling in the right hand had prominent facial myokymia. Magnetic resonance imaging revealed syringomyelia and syringobulbia. After successful syringosubarachnoid shunting, the patient died of massive pulmonary embolism. Postmortem examination revealed a syrinx involving the spinal cord and lower half of the medulla; neither the facial nucleus nor facial nerve fibers were directly involved. We hypothesize that interruption of aberrant corticobulbar fibers in the medulla produced disinhibition of a rhythmic neural generator in the facial nucleus.

Adult↗

PubMed1989

Sparing of the flexor carpi ulnaris in ulnar neuropathy at the elbow.

A common misconception attributes sparing of the flexor carpi ulnaris (FCU) in ulnar neuropathy at the elbow (UNE) to its innervating branch arising "at or above the elbow." We examined the relationship of FCU branches to the medial epicondyle (ME) and humeroulnar aponeurotic arcade (HUA) in 30 cadaver elbows. In only three did the first FCU branch arise at or proximal to the ME. In 36 UNE cases with fibrillations in the first dorsal interosseous, the FCU was normal in 10, mildly abnormal in 11, and severely abnormal in 15. FCU involvement correlated with the severity of the neuropathy and with whether compression was retroepicondylar or at the HUA. We conclude that sparing of the FCU in UNE is unrelated to the level of origin of its innervating branch, but rather is related to the internal neural topography and to the severity and level of compression.

Elbow↗

PubMed1988

Intraoperative electroneurography: management of ulnar neuropathy at the elbow.

At the elbow the ulnar nerve may be compressed either in the retrocondylar groove or at the cubital tunnel. Optimal surgical therapy should be directed at the specific site of involvement. Intraoperative electroneurography performed in conjunction with 19 ulnar nerve explorations helped localize the precise site of compression. Of the primary procedures, abnormality was at the retrocondylar groove in 9, cubital tunnel in 4, both locations in 3, and at an unusual distal point in 1; 12 anterior subcutaneous transpositions, 4 cubital tunnel releases, and 1 distal decompression resulted. Intraoperative studies helped identify residual compression in two patients undergoing reexploration. Although routine electrodiagnosis may localize an ulnar neuropathy to the elbow, reliably separating retrocondylar from cubital tunnel compression is more difficult. Preoperatively, percutaneous serial short increment studies were more accurate than simple "inching" in predicting the site of compression.

Diagnosis, Differential↗