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Subclinical organic psychosyndromes on intrathecal injection of metrizamide for lumbar myelography.

Eighteen patients with symptoms and signs of possible lumbar disc herniation, who had no evidence of a preexisting organic psychosyndrome were included in the study. An organic psychosyndrome was found in six of them 10 h after lumbar myelography with metrizamide. The psychosyndrome, which was characterized by impaired memory and depression, could be demonstrated only by psychometric methods. In these patients metrizamide could be demonstrated within the basal cisterns by computed tomography 8 h after lumbar injection of the contrast medium. The organic psychosyndrome was completely reversible; five days after myelography it could not be detected any more by psychometric means. The development of an organic psychosyndrome in six of the 18 patients suggests a neurotoxic effect of metrizamide. This assumption is supported by hypo- and areflexia in four patients after intrathecal metrizamide as well as by EEG changes seen in three patients after myelography. There was no correlation between the EEG changes or reflex abnormalities and the organic psychosyndrome.

Adult↗

Long latency muscle responses in cerebellar diseases.

Long latency reflexes were measured from the hand muscles of 27 patients suffering from different cerebellar diseases (12 diffuse cerebellar atrophies, 7 cerebellar hemispheric infarcts, 8 Friedreich's disease) and from 45 controls after electrical stimulus of the median nerve at the wrist. The M3 response (latency about 70 ms) was increased in about 50% of cerebellar atrophy cases and occasionally (10 of 12 cases) separated from the M2 response (50 ms). M3 was sometimes (3/7) increased and the M2-3 complex was prolonged ipsilaterally in cases of cerebellar infarcts. In the cases of Friedreich's ataxia M2 was always lost uni or bilaterally because of the disturbance of afferent or efferent fibres. The latencies of the spinal reflex M1 and also of M2 were not always increased strongly enough to be clearly separated from the normal values.

Adult↗

A case report of congenital hypomyelination.

A 3 year, 11 month-old Japanese male with congenital hypomyelination is described. Clinical features are delay of motor development, generalized muscle hypotonia and weakness, absent tendon reflexes due to peripheral neuropathy, and normal mental development. Electrophysiologically, nerve conduction velocities could not be measured. Histological examination of the right sural nerve revealed total of absence myelin of most of the myelinated fibers. Electronmicroscopically, there was a concentric network of lamellae formed by double-layered sheets of basement membranes with fragments of Schwann cell cytoplasm around the myelinated fibers, so called "onion-bulbs". These peculiar features were similar to those in the cases reported by Lyon, (1969); Kennedy et al., (1977); Karch et al., (1975); and Anderson et al. (1973).

Biopsy↗

Clinical and electrophysiological study of the peripheral nervous system in the elderly.

The effect of age on the peripheral nervous system was investigated by clinical examination and neurophysiological studies in 59 subjects aged 60-103 years and 23 young subjects. A full laboratory screen for factors which, though clinically silent, may constitute risk factors (RFs) for peripheral neuropathy was also performed in the elderly subjects. Our findings show that the presence of RFs affects exceptionally the electrophysiological parameters in a statistically significant way. The age-dependent changes in nerve conduction parameters were well predicted by non-linear models. The simultaneous electromyographical study demonstrates the re-innervation capacity of the motor system.

Action Potentials↗

Trigeminocardiac reflexes: maxillary and mandibular variants of the oculocardiac reflex.

Three case reports are presented to illustrate the existence and importance of reflex bradycardic responses that can occur during maxillofacial surgical procedures. All three patients were healthy young adults undergoing operations which did not include any manipulation of orbital structures. After the patients had been anaesthetized for some time and were haemodynamically stable, profound bradycardia or ventricular asystole occurred suddenly in response to manipulations of the bony structures of the maxilla or mandible, or dissection of, or traction on, the attached soft tissue structures. The parasympathetic supply to the face is carried in the trigeminal nerve. Alternative afferent pathways must exist via the maxillary and/or mandibular divisions, in addition to the commonly reported pathway via the ophthalmic division of the trigeminal nerve in the classic oculocardiac reflex. The efferent arc involves the vagus, regardless of which branch of the trigeminal nerve transmits the afferent impulses. All patients undergoing maxillofacial procedures should be monitored carefully for reflex bradycardia and ventricular asystole.

Adult↗

Lumbosacral plexopathy from iliopsoas haematoma after combined general-epidural anaesthesia for abdominal aneurysmectomy.

PURPOSE: To report a case of iliopsoas haematoma after resection of an abdominal aortic aneurysm which resulted in a lumbosacral plexopathy. CLINICAL FEATURES: An 81-yr-old man presented with an abdominal aortic aneurysm for aneurysmectomy and tube grafting. An epidural catheter was placed at the L1-2 spinal level and combined epidural-general anaesthesia was provided for surgery. The surgery was complex and a suprarenal clamp was necessary to obtain proximal control. A continuous infusion of demerol through the epidural catheter was prescribed for postoperative analgesia. On the first postoperative day, examination revealed a paretic, pulseless right leg and he was returned to the operating room for femoral-femoral bypass. By the following day, the motor and sensory impairment had progressed to complete paralysis with loss of all deep tendon reflexes and absent sensation below L1, despite palpable pulses in the leg. A CT of the abdomen demonstrated a right iliopsoas haematoma. There was no evidence of either disc herniation or an epidural haematoma. A diagnosis of lumbosacral plexopathy secondary to a iliopsoas haematoma was made. CONCLUSION: Iliopsoas haematoma is a rare cause of postoperative neurological deficit following aortic vascular surgery. The haematoma results in compression of the lumbosacral neural elements and typically presents as a femoral neuropathy. The diagnosis is clinical and can be readily validated with computed tomography.

Aged↗

Impaired classical eyeblink conditioning in elderly human subjects: the role of unconditioned response magnitude.

BACKGROUND AND AIMS: Classical conditioning is impaired in elderly subjects, and an experiment investigated the role of unconditioned response magnitude and autonomic arousal in this aging-related impairment. METHODS: Two groups of young (n = 20, mean age 23.8 years) and elderly (n = 21, mean age 73.8 years) healthy subjects participated in the experiment. Single-cue classical eyeblink conditioning was in effect for 72 trials, with a tone as the conditioned stimulus (CS) and an airpuff to the eye as the unconditioned stimulus (US). The CS was presented alone in eight additional trials to allow recordings of skin conductance and heart rate responses. Startle eyeblink reflexes were elicited either alone or in the presence of the CS after the end of the conditioning procedure to investigate startle potentiation. RESULTS: More young (95%) than elderly (76%) subjects identified the CS - US contingency in a post-conditioning questionnaire, whereas only 38% of the elderly and 85% of the young subjects acquired the conditioned response (CR). Unconditioned blink reflex magnitudes were greater in the subjects who had acquired the CR. Heart rate deceleration was seen in both young and elderly subjects who had acquired the conditioned response. Startle reflexes and skin conductance responses were related to conditioning in young but not in elderly subjects. CONCLUSIONS: Unconditioned response magnitude was the best predictor for the acquisition of the CR. Together with the questionnaire data, this indicates that peripheral factors play a significant role in the impairment of classical eyeblink conditioning in elderly people. Autonomic arousal was not related to acquisition of the CR in elderly subjects.

Adolescent↗

[Physical therapy to treat spinal stenosis].

Spinal stenosis mainly is a disease of the elderly. In most cases the lumbar spine is affected. The assessment is based on the typical constellation of symptoms (neurogenic claudication, subjective weakness) and physical findings (abnormal reflex status, loss of strength, sensory deficits, impairment in balance and coordination). The diagnosis is further supported by the radiologic proof of a stenosis of the spinal canal, the lateral recess, and the intervertebral foramina. The main targets of physical and rehabilitative medicine are the relief of pain and an improvement in the activities of daily living, which are especially impaired by reduced walking distance and difficulties in climbing stairs. These can be achieved by multimodal, conservative management: physiotherapy, occupational therapy, treatment of myofascial disorders, and oral medication/local injections. Physiotherapy aims at a stabilization of the lumbar spine in a flexed posture rather than in lumbar lordosis and at an increase of overall physical fitness. Oral analgetic and/or anti-inflammatory medical management is based on the three-step scheme of the World Health Organization, which also can be applied for low back pain. Local injections can help to control symptoms. Myofascial disorders are treated by techniques and procedures such as traditional massage.

Activities of Daily Living↗

The tonic stretch reflex and spastic hypertonia after spinal cord injury.

The operational definition of spasticity is focused on increased resistance of joints to passive rotation and the possible origin of this increased resistance in the induced tonic stretch reflex (TSR). This term is applied in the context of both cerebral and spinal injury, implying that a similar reflex mechanism underlies the two disorders. From recent studies it is clear that increased passive joint resistance in resting limbs following stroke is highly correlated with the induced TSR, but this evidence is lacking in spinal injury. The contribution of the TSR to hypertonia in spinal cord injury (SCI) is unclear and it is possible that hypertonia has a different origin in SCI. The contribution of resting and activated TSR activity to joint stiffness was compared in SCI and normal subjects. The magnitude of the TSR in ankle dorsiflexors (DF) and plantarflexors (PF) and mechanical ankle resistive torque were measured at rest and over a range of contraction levels in normal subjects. Similar measures were made in 13 subjects with SCI to the limits of their range of voluntary contraction. Normals and SCI received a pseudo-sinusoidal stretch perturbation of maximum amplitude +/- 20 degrees and frequency band 0.1-3.5 Hz that was comparable to that used in manual clinical testing of muscle tone. Elastic resistance and resonant frequency of the ankle joint, after normalization for limb volume, were significantly lower in complete and incomplete SCI than normal subjects. No reflex response related to stretch velocity was observed. Resting DF and PF TSR gain, when averaged over the tested band of frequencies, were significantly lower in complete SCI than in resting normal subjects (<0.5 microV/deg). Linear regression analysis found no significant relationship between TSR gain and resting joint stiffness in SCI. Mean TSR gain of DFs and PFs at rest was not correlated with the subject variables: age, time since SCI, level of injury, Frankel score, number of spasms per day, Ashworth score or anti-spastic medication. DF and PF reflex gain were linearly related to voluntary contraction level and regression analysis produced similar slopes in incomplete SCI and normal subjects. Hence TSR loop gain was not significantly increased in SCI at any equivalent contraction level. Extrapolation of the regression lines to zero contraction level predicted that reflex threshold was not reduced in SCI. Low frequency passive stretches did not induce significant TSR activity in the resting limbs of any member of this SCI group. The TSR thus did not contribute to their clinical hypertonia. Other reflex mechanisms must contribute to hypertonia as assessed clinically. This result contrasts with our similar study of cerebral spasticity after stroke, where a comparable low frequency stretch perturbation produced clear evidence of increased TSR gain that was correlated with the hypertonia at rest. We conclude that a low frequency stretch perturbation clearly distinguished between spasticity after stroke and SCI. Spasticity in the two conditions is not equivalent and care should be taken in generalizing results between them.

Adult↗

Effect of unilateral vestibular deafferentation on the initial human vestibulo-ocular reflex to surge translation.

Transient whole-body surge (fore-aft) translation at 0.5 G peak acceleration was administered to six subjects with unilateral vestibular deafferentation (UVD), and eight age-matched controls. Subjects viewed eccentric targets to determine if linear vestibulo-ocular reflex (LVOR) asymmetry might lateralize otolith deficits. Eye rotation was measured using magnetic search coils. Immediately before surge, subjects viewed a luminous target 50 cm away, centered or displaced 10 degrees horizontally or vertically. The target was extinguished during randomly directed surges. LVOR gain relative to ideal velocity in subjects with UVD for the contralesional horizontally eccentric target (0.59 +/- 0.08, mean +/- SEM) did not differ significantly from normal (0.50 +/- 0.04), but gain for the ipsilesional eccentric target (0.35 +/- 0.02) was significantly less than normal (0.48 +/- 0.03, P < 0.05). Normal subjects had mean gain asymmetry for horizontally eccentric targets of 0.17 +/- 0.03, but asymmetry in UVD was significantly increased to 0.35 +/- 0.05 (P < 0.05). Four of six subjects with UVD had maximum gain asymmetry outside normal 95% confidence limits. Asymmetry did not correlate with UVD duration. Gain for 10 degrees vertically eccentric targets averaged 0.38 +/- 0.14 for subjects with UVD, insignificantly lower than the normal value of 0.75 +/- 0.15 (P > 0.05). Surge LVOR latency was symmetrical in UVD, and did not differ significantly from normal. There was no significant difference in response between dark and visible target conditions until 200 ms after surge onset. Chronic human UVD, on average, significantly impairs the surge LVOR for horizontally eccentric targets placed ipsilesionally, but this asymmetry is small relative to interindividual variation.

Acceleration↗

Constant involvement of the Betz cells and pyramidal tract in amyotrophic lateral sclerosis with dementia: a clinicopathological study of eight autopsy cases.

We investigated clinicopathologically pyramidal signs, including hyperreflexia, Babinski sign, and spasticity, and the involvement of the primary motor cortex and pyramidal tract, in eight Japanese autopsy cases of amyotrophic lateral sclerosis (ALS) with dementia. Pyramidal signs were observed in seven (88%) of the eight autopsy cases. Hyperreflexia and Babinski sign were evident in seven (88%) and three (38%) patients, respectively, but spasticity was not observed in any of the eight patients. Loss of Betz cells in the primary motor cortex was evident in the seven cases in which this structure was examined. Astrocytosis in the fifth layer of the primary motor cortex was noticed in three cases. In all eight cases, involvement of the pyramidal tract was obvious in the medulla oblongata, but no involvement of the pyramidal tract was found in the midbrain. Involvement of the pyramidal tract in the spinal cord, particularly of large myelinated fibers, was observed in all six cases in which the spinal cord was examined. In ALS with dementia, pyramidal signs were shown to be present more frequently than previously believed, and the clinicopathological correlation between pyramidal signs and involvement of the pyramidal tract was obvious. Constant involvement of Betz cells and the pyramidal tract in ALS with dementia has not been reported. Our clinicopathological findings may make a contribution to the understanding of the clinicopathological hallmarks of this disorder. Furthermore, we believe that this study will also contribute to the elucidation of the nosological status of ALS with dementia.

Adult↗

Constant and severe involvement of Betz cells in corticobasal degeneration is not consistent with pyramidal signs: a clinicopathological study of ten autopsy cases.

This report concerns a clinicopathological study of three additional patients with corticobasal degeneration (CBD), described here for the first time, and a clinicopathological correlation between pyramidal signs and upper motor neuron involvement, in ten autopsy cases of CBD, including seven cases reported by us previously. We investigated pyramidal signs, including hyperreflexia, Babinski sign, and spasticity, and involvement of the primary motor cortex and pyramidal tract, focusing on the astrocytosis of the fifth layer of the primary motor cortex. Pyramidal signs were observed in six (60%) of the ten cases. Hyperreflexia was evident in six patients (60%), with spasticity being observed in three patients (30%). Loss of Betz cells associated with prominent astrocytosis and presence of ballooned neurons in the fifth layer of the primary motor cortex was observed in all ten cases. In all cases, involvement of the pyramidal tract was obvious in the medulla oblongata, without involvement of the pyramidal tract in the midbrain. Constant and severe involvement of the fifth layer of the primary motor cortex, including the Betz cells, has not previously been reported in CBD. We suggest that the pyramidal signs in CBD have been disregarded.

Aged↗

Compound heterozygosity and nonsense mutations in the alpha(1)-subunit of the inhibitory glycine receptor in hyperekplexia.

The alpha(1)-inhibitory glycine receptor is a ligand-gated chloride channel composed of three ligand-binding alpha1-subunits and two structural beta-subunits that are clustered on the postsynaptic membrane of inhibitory glycinergic neurons. Dominant and recessive mutations in GLRA1 subunits have been associated with a proportion of individuals and families with startle disease or hyperekplexia (MIM: 149400). Following SSCP and bi-directional di-deoxy fingerprinting mutational analysis of 22 unrelated individuals with hyperekplexia and hyperekplexia-related conditions, we report further novel missense mutations and the first nonsense point mutations in GLRA1, the majority of which localise outside the regions previously associated with dominant, disease-segregating mutations. Population studies reveal the unique association of each mutation with disease, and reveals that a proportion of sporadic hyperekplexia is accounted for by the homozygous inheritance of recessive GLRA1 mutations or as part of a compound heterozygote.

Amino Acid Sequence↗

Freezing of gait in patients with advanced Parkinson's disease.

BACKGROUND: Freezing of Gait (FOG) is one of the most disturbing and least understood symptom in advanced stage of Parkinson's disease (PD). The contribution of the underlying pathological process and the antiparkinsonian treatment to the development of FOG are controversial. OBJECTIVE: To study the relationships between clinical features of PD and therapeutic modalities in patients with advanced PD and FOG. METHODS: Consecutive patients with 5 years or more of PD symptoms (n = 172) (99 men) with mean age at symptoms onset of 58.3 +/- 13.2 years and mean symptoms duration of 11.8 +/- 5.6 years were studied. Clinical data were collected during the last office visit through physical examination, detailed history, review of patients' charts, and other documents. A patient was considered as "freezer" if he/she reported recent experience that the legs got stuck to the ground while trying to walk. The presence of dyskinesia, early morning dystonia or significant postural reflex abnormalities were assessed through history and neurological examination. Duration of treatment with antiparkinsonian drugs was calculated from history charts. Chi square and t test were used to compare the patients with and without FOG. Logistic regression was used for the comparison of association between the presence of FOG (dependent variable) disease duration and disease stage (explanatory variables) and duration of treatment with anti-parkinsonian drugs. RESULTS: The study population consisted of 45 patients at Hoehn and Yahr (H&Y) stage 2.5 (26%), 104 patients at stage 3 (60.5%), and 23 patients at H&Y stages 4-5 (13.5%). Ninety one patients (53%) reported FOG at the time of the study. Severity of the disease expressed by H&Y stage at "off" was a significant contributing factor for FOG with a significant trend (z = 4.38, p < 0.0001), as was longer duration of levodopa treatment, and confirmed by FOG using the multivariate logistic regression (p = 0.01 and p = 0.004, respectively). Using a univariate model, longer duration of treatment with dopamine agonists contribute to the appearance of FOG (p = 0.07) while longer duration of amantadine treatment decreased the appearance of FOG (p = 0.09). There was a significant association between FOG and the presence of dyskinesia (p < 0.002), early morning foot dystonia (p < 0.003) and significant postural instability (p < 0.0005). CONCLUSION: FOG is a common symptom in advanced PD. It is mainly related to disease progression and levodopa treatment.

Adult↗