Biomedical subjects

A Beric

Publications and source records attributed to A Beric.

26 records · Page 2Linked to original sources

PubMed1992

Detrusor function with lesions of the conus medullaris.

Conventional urodynamic evaluation is unable to distinguish between a pure conus lesion and one with concomitant cauda equina involvement. Lumbosacral evoked potentials to tibial nerve stimulation assesses the sensory root and dorsal horn interneurons of the L5 to S2 spinal cord segments. This allows for the diagnosis of a pure lesion of the conus medullaris with preservation of the sensory root response (R wave) with absence of the dorsal horn gray matter response (S wave). Urodynamic evaluation in 5 patients with a conus lesion showed a variety of detrusor responses ranging from hyperreflexia through areflexia with decreased compliance to areflexia with normal compliance. The ability to diagnose a pure conus lesion may have prognostic significance as newer modalities of treatment emerge, all of which require intact gray matter of the spinal cord.

Adult↗

PubMed1992

Detrusor function in suprasacral spinal cord injuries.

A total of 21 patients with chronic, stable suprasacral spinal cord injuries underwent a comprehensive neurological evaluation. A second lumbosacral lesion was excluded. The urodynamic findings were relatively constant as 95% of the patients showed detrusor hyperreflexia with elevated pressures, sphincteric dyssynergia and a competent bladder neck during the filling phase. The urodynamic findings of unexpected detrusor function in high spinal cord injury, for example areflexia and hypocontractility, should raise the clinician's suspicion that there is a lesion or dysfunction involving the sacral cord.

Adolescent↗

PubMed1992

Function of the conus medullaris and cauda equina in the early period following spinal cord injury and the relationship to recovery of detrusor function.

A total of 26 patients with an early suprasacral spinal cord injury underwent comprehensive neurourological evaluation to determine if there was any correlation between the return of detrusor function and neural function of the sacral cord. In addition, the incidence of a subclinical sacral neural dysfunction early after spinal cord injury was assessed. Lumbosacral evoked potentials to tibial nerve stimulation were used to assess the sensory root and cord gray matter of the L5 to S2 segments, while urodynamic evaluation was performed to assess detrusor function. Of those patients with normal lumbosacral evoked potentials 82% recovered detrusor contractility as opposed to 66% with abnormal evoked potentials. Four patients (23.5%) had persistent detrusor areflexia when studied 9 to 20 months following the acute injury. The potential problems attempting to correlate the neurophysiological and urodynamic studies are multiple and are extensively discussed. Despite these potential problems the return of detrusor function correlated well with associated normal lumbosacral evoked potentials suggesting that this test can be used in the early phase following spinal cord injury to predict return of bladder function, since it is independent of the level of spinal cord excitability. Of the patients studied 38% had coexistence of an occult lumbosacral dysfunction. This rate is higher than that found in the chronic stabilized spinal cord injury population (20.5%), since the cases in our study may represent a more severe lesion.

Adolescent↗

PubMed1992

Motor nerve inexcitability in Guillain-Barré syndrome. The spectrum of distal conduction block and axonal degeneration.

We studied 34 patients with the Guillain-Barré syndrome (GBS) to clarify the clinical significance of inexcitable motor nerves and of low amplitude compound muscle action potentials (CMAPs). The patients were subdivided into two groups. Group 1 included eight patients who had electrically inexcitable motor nerves within 2 wks of the first symptom. (Two patients without extensive conduction studies had only one inexcitable motor nerve.) The outcome in this group at 1 yr varied from complete recovery (five patients) to severe motor sequelae (three patients). Group 2 included 26 patients who had two electrophysiological assessments, and in whom the serial changes in CMAP amplitudes were analysed and correlated to outcome. Fourteen of these 26 sets of serial studies were performed within 1 mth. Twelve of 26 patients in Group 2 showed decrease in the amplitude of CMAPs between serial studies; only six of these had a good outcome at 1 yr. Nine of 26 patients showed increase in CMAP amplitude between serial studies, of these eight had a good clinical outcome. Low-amplitude CMAPs or inexcitable motor nerves in the initial stages of GBS are due to distal pathology of the motor axons, either distal conduction block or axonal degeneration. The nature of these changes cannot be predicted by the results of the initial electrophysiological evaluation, including the presence or absence of active denervation. However, improvement of CMAP amplitude on sequential studies suggests a good outcome at 1 yr. We believe that, in the absence of a biological marker for GBS, individualization of an 'axonal variant' of the syndrome is not warranted at the present time.

Action Potentials↗

PubMed1989

Direct spinal effect of a benzodiazepine (midazolam) on spasticity in man.

The water-soluble benzodiazepine, midazolam, was administered epidurally over the lumbar enlargement 18 times to 9 patients with spasticity due to severe spinal cord injury. Doses of 1.25-3.75 mg produced a rapid decrease of spasticity which lasted 1 h. After the maximal reduction of spasticity, the patients became drowsy. While the results suggest a direct action of midazolam on the spinal cord to reduce spasticity, the effect does not contribute to its usefulness as a therapeutic tool.

Adult↗

PubMed1987

Predictive criteria for failed sphincterotomy in spinal cord injury patients.

Nine patients with chronic high spinal cord injury who failed sphincterotomy secondary to detrusor hypocontractility underwent neurourological evaluation. Testing revealed an abnormality involving the sensory limb of the somatic sacral reflex arc (abnormal R wave) or at the level of the spinal interneuron pool (abnormal or absent S wave). This study strongly suggests that the sensory input from the bladder to the spinal cord, together with alteration in the sensory motor integration that occurs at the level of the interneuron pool, is important in influencing the characteristics of the detrusor contraction following high spinal cord injury. Predictive criteria for failed sphincterotomy are a slow increase to maximum intravesical pressure before voiding and abnormal lumbosacral sensory evoked potentials.

Adolescent↗

PubMed1985

Detrusor areflexia in suprasacral spinal cord injuries.

Patients with high thoracic or cervical spinal cord injuries normally have a detrusor contraction during cystometry. Thirteen patients with detrusor areflexia and a high spinal cord lesion underwent neurophysiological evaluation with electromyography of the pelvic floor muscles, lumbosacral-evoked potential to tibial nerve stimulation, the bulbocavernosus reflex and water cystometry. Two groups of patients were identified. Of those patients with initial detrusor areflexia evidence was found for a subclinical second lesion involving the lumbosacral arc, which accounted for the acontractile bladder. In the remaining patients of this group, who had an intact sacral reflux arc, a detrusor contraction developed after a mean of 16.6 months from the date of injury. The second group of patients exhibited initial detrusor hyperreflexia that subsequently converted to areflexia. A reason was found for the alteration in bladder behavior in each case. The possible reasons for differential recovery of the somatic and autonomic nervous systems are discussed together with a rationale for the second subclinical spinal cord lesion. The most predictive neurophysiological test was electromyography of the pelvic floor.

Adolescent↗

PubMedDate not supplied

Electrically evoked long loop responses (LLR): normative data for upper and lower extremities.

Long loop responses can be obtained repeatedly in all neurologically healthy subjects with low variability of onset and peak latencies. Long loop responses showed characteristic features separate from microreflexes of Bickford. Normative data will help us to elucidate the characteristic alterations of these reflexes in different pathologies which involve somatosensory pyramidal and extrapyramidal systems.

Adolescent↗