Far-out foraminal stenosis with radiculopathy caused by bony spur formation secondary to anomalous articulation between the transverse process and the sacral ala is rarely reported. We report two cases of unilateral far-out foraminal entrapment of the L5 spinal nerve below a transitional vertebra, with a review of the literature. The objective of this work was to describe the management of a rare far-out foraminal stenosis below a transitional vertebra and to evaluate the surgical and conservative procedures and results. In a previous article, decompression was performed through an anterior approach. However, we report no difficulty with decompression using a posterior approach for one patient. The diagnosis was confirmed with computed tomography, magnetic resonance imaging, and selective radiculography. First, selective nerve root blocks were performed in two cases for the purpose of nonoperative treatment. After failure of conservative treatment with selective nerve root block, one patient underwent posterior decompression by resection of the bony spur using a posterior approach. One patient obtained good relief of radicular pain with only selective nerve root block. The other patient obtained good relief of radicular pain after posterior decompression was performed. Posterior decompression through the posterior approach is an easy, safe, and useful treatment for radicular pain caused by an L5 nerve far-out foraminal stenosis below a transitional vertebra when conservative treatments have failed to obtain good relief of radicular pain.

Transcranial Magnetic stimulation can elicit amuscle response (MEP) from the target muscle with a voluntary contraction. MEPs were recorded from nineteen patients with cervical myelopathy due to single level compressin of the spinal cord. Central motor conductino time (CMCT) was also measured by subtracting the peripheral conduction time from the onset latencies of the MEPs.These methods were performed in biceps brachii (BB) muscles and abductor digit minimi muscles (ADM). The CMCT of BB and ADM were delayed in the cases with cord compression at C1/2 level. The CMCT of ADM was markedly delayed compared to that of BB in the cases with cord compression at C3/4 level. The CMCT of only theADM was delayed in the cases with cord compression at C4/5 and C5/6 levels. These results showed that comparison of the CMCT between the BB and the ADM is useful in the clinical diagnosis of the level of cervical myelopathy.

We examined whether the recruitment properties of the corticospinal pathway to forearm muscles are influenced by variations of the shoulder joint angle. Flexor carpi radialis (FCR) and extensor carpi radialis (ECR) muscles motor evoked potentials (MEPs) in response to transcranial magnetic stimulation were examined during different static positions of shoulder joint in the horizontal plane: from 30° abduction to 30° adduction. We found that at 30° shoulder adduction, maximum slope and plateau phase of the ECR and FCR input–output relationship (i.e., relation between MEP size and stimulus intensity) were significantly higher and lower than at 30° abduction of the shoulder joint, respectively. Intracortical inhibition (ICI) and intracortical facilitation (ICF) of the FCR were assessed using a paired-magnetic pulse paradigm. A significant decrease in ICF was observed after changing shoulder position from 30° abduction to 30° adduction. On the contrary, no variation in the amount of ICI occurred in relation to the same changes in shoulder position. FCR H-reflex to electrical stimulation of median nerve at elbow did not differ significantly between the two shoulder positions. We conclude that shoulder position influences the recruitment efficiency (gain) of the corticospinal volleys to motoneurones of forearm muscles. It is proposed that activity of peripheral receptors signaling static shoulder position influences corticomotor excitability of forearm muscles mainly at cortical level, although C3–C4 propriospinal system could be also involved. It is proposed that the above changes in corticomotoneuronal excitability to forearm muscles as function of shoulder joint position are part of a global proximal–distal synergy operating throughout reaching movements.

In general, configuration of M-wave shows a simple dome-shape by belly-tendon montage. The M-wave recorded over the hypothenar eminence elicited by ulnar naerve stimulation often has double peaks in the negative phase. The origin of this double-peaked response has not been clarified. To investigate the origin of these double peaks, we recorded ulnar M-waves from abductor digiti minimi, 1st dorsal interossei, and adductor pollicis simultaneously in 11 hands of six normal volunteers, in two cases of Guyon's canal syndrome and in two cases of ulnar nerve injury at the wrist. In the seven hands of normal volunteers, we recorded double-peaked M-waves from abductor digiti minimi. The latency of the second peak corresponded to the peak latency of the 1st dorsal interossei and adductor pollicis. In the two cases of Guyon's canal syndrome and in the two cases of ulnar nerve injury at the wrist, M-waves from abductor digiti minimi were a simple domeshape. In those cases M-waves from the 1st dorsal interossei and adductor pollicis were almost absent. We concluded that M-waves from the 1st dorsal interossei and adductor pollicis influenced the second peak of the M-wave recorded over the hypothenar eminence.

Cervical spondylosis with muscle atrophy in the shoulder girdle is called cervical spondylotic amyotrophy. Pathophysiology in this condition is not well resolved. Muscle action potential after stimulation of the cortex by magnetic stimulation (MEP) in biceps brachii and T-response muscle action potential after tapping of biceps tendon were recorded in 10 patients who presented with deltoid and biceps paresis. Latency difference between the affected and unaffected side were also measured. Latency differences were more evident in T-response compared to MEP. The results showed that pathological lesions in cervical spondylotic amyotrophy are not localized to the anterior root but also found in the spinal cord or posterior root.

Magnetic stimulation at the head were applied to the two patients of hysterical paresis. It was difficult to elicit motor evoked potentials (MEPs) from paretic muscle at rest. It was able to record MEPs from paretic muscle during voluntary contraction of contralateral limb. We applied magnetic stimulation in the six healthy volunteers of intentional paresis on left hand (simulation).Simulation was continued 8-12 hours. After simulation amplitude of MEPs from left thenar eminence were reduced to 10-50%. It suggesed that motoneuron excitability in cases of hysterical paresis and simulation was inhibited.

In order to diagnose the level of nerve root injury, we intraoperatively recorded spinal evoked potentials (SpEP) in 13 cases of brachial plexus injury. The recording electrode, the catheter electrode was inserted into the epidural space the day before surgery. Nerve roots were stimulated directly after exposure. No response was obtained after stimulation in those damaged nerve roots having an abnormal myelogram or with abnormal macroscopic findings. There were 5 cases of nerve transplantation from the C5 root to the peripheral nerve. Good responses (amplitude 10μ V, 15μ V) were recorded in 2 cases from the epidural electrode after C5 root stimulation. Motor unit potentials in the muscle innervated by the C5 root appeared in these 2 cases after nerve transplantation. No response was recorded in 2 cases and a very small response in one case from the epidural electrode after C5 root stumulation. In these 3 cases motor unit potentials were not obtained.It was concluded that intraoperative SpEP recordings are very useful in documenting functional continuity between spinal cord and nerve root in cases of brachial plexus injuty.

We report a new techique for correction of idiopathic scoliosis using percutaneous nucleotomy (P. N.).Four patients with idiopathic thoracolumbar scoliosis, had P. N. under local anesthesia. Subjects were four females, ranging in age from 13 to 17 years. Preoperative curve was from 28° to 41° in the standing position without corrective braces.P. N. was done at two disc levels, above and below the apex. These disc levels were confirmed as the transposition of the nucleus to the convex side by magnetic resonance imaging.Post-operatively all patients improved on average by 9.5°, ranging from 8° to 10°. No patients complained of severe pain during or after the operation.The transposition of the nucleus to the convex side is considered to be a mechanical disturbance to correction.P. N. in thocaco-lumber scoliosis is relatively safe and technically easy because of transposition of the nucleus, opening of disc space on the convex side, and rotation of the vertebral body. Percutaneous nucleotomy with a corrective brace is expected to be a new treatment for thoraco-lumbar scoliosis.

In cervical spondylosis typical electromyographic findings are 1) normal insertional activity, 2) no spontaneous activity, 3) normal motor unit potential (MUP), and 4) reduced interference pattern with slow rates of firing of individual MUPs. We examined spontaneous activity (fibrillation potential) from deltoid, biceps brachii, triceps branchii, abductor pollicis brevis and abductor digiti minimi in 10 cases of cervical spondylotic myelopathy and 5 cases of cervical spondylotic amyotrophy. Fibrillation potentials were recorded from one muscle (abductor pollicis brevis) in 10 cases of cervical spondylotic myelopathy. Fibrillation potentials were recorded from eight muscles (deltoid 4, biceps branchii 3, triceps branchii 1) in 5 cases of cervical spondylotic amyotrophy. All muscles which had fibrillation potentials were atophic. MMT of those muscles were poor. Fibrillation potentials in cervical spondylosis indicate necrosis of anterior horn cell or degeneration of radix ventralis.

In order to evaluate spinal spasticity quantitively, we recorded the T waves of the patella tendon reflex following the Jendrassik manoeuvre and at rest, and measured the ratio of the amplitude of T wave (J/R ratio).The J/R ratio of 8 normal subjects ranged from 1.89 to 10.3 (mean: 4.60), and in 12 patients with spinal spasticity ranged from 1.0 to 1.88 (mean: 1.28).The more the spasticity increased, the closer to 1.0 the J/R ratio tended to be.

Latency and wave form of M-responses change in entrapment neuropathy, because of segmental demyelination and axonal degeneration. Normally, latency decreases gradually (0.2ms/cm) as the cathode moves proximally and the wave form does not change due to the phase cancellation having little influence. In entrapment neuropathy a steep latency change occurred across the entrapment point and in many cases the wave form changed across the entrapment point, influenced by the increasing phase cancellaltion.

The function of sural nerve in 6 cases of myelopathy and in 15 cases of spinal cord injury was assessed by recording the amplitudes of sensory nerve action potentials (SNAPs) and conduction velocities. In 6 cases of myelopathy and in 12 cases of spinal cord injury SNAPS were obtained. In all cases of myelopathy and in g cases of spinal cord injury the amplitude of sural SNAPS remained within the normal range. Sensory conduction velocities were generally normal when obtainable. If the amplitude of SNAPs are below the normal range in the cases of myelopathy or spinal cord injury, we have to consider the complication of the peripheral nerve damage.

Eleven hips (8 cases) with chronic slipped capital femoral epiphysis were treated depending on their degree of displacement. Two cases with slight and moderate slip were treated conservatively, the other 9 hips were surgically treated. Pinning in situ was performed for 4 hips with mild slips and Southwick's trochanteric osteotomy and Sugioka's anterior rotational osteotomy was carried out for 4 hips with moderate and severe slips. One case with a severe slip (Posterior Tilt Angle=75 degree) was surgically treated by Sugioka's anterior rotational osteotomy with modified Kramer's method, which was safer and corrected the severe deformity better than the other methods.Follow-up averaged 2 years and 10 months, with all patients obtaining a satisfactory clinical result. Although the clinical result was excellent in two conservatively treated cases, the range of internal rotation of these hip joints was restricted. However this limitation only correlated with obesity.We concluded the following indications for treatment of chronic SCFE.<40 degrees: in situ pinning, 40-70 degrees: trochanteric osteotomy, >70 degrees: anterior rotational osteotomy+modified Kramer's method.

An experimental study was carried out on the electrophysiology and histology of spinal cord traction. In 5 kittins and 12 adult cats, spinal cord traction impairment was created by gradual lumbosacral cord traction. The spinal cord vulnerability was different in the kitten compaied, to the adult cat.

We recorded some potentials from the gastrocunemius muscle and sciatic nerve elicited by epidural electrical stimulation in ten cats. Stimulating electrodes were placed in the epidural space at the level of the seventh thoracic vertebra. Recording electrodes were placed into the gastrocunemius muscle and sciatic nerve.After cut of the tibial nerve, no remarkable change was seen on the so-called motor evoked potentials from gastrocunemius muscle.No response was recorded from sciatic nerve after making lesions of dorsal roots at the level from L5 to L7.These results suggest that we can't record motor evoked potentials from anesthetized cats by epidural stimulation on the thoracic spinal cord level.

Compound muscle action potentials (CMAPs) were recorded in tibialis anterior, extensor digitorum brevis and abductor hallucis elicited by stimulation of the cauda equina. We examined twenty patients with intermittent claudication due to lumbar canal stenosis. For the purpose of analyzing the alteration on the cauda equina propergation, we recorded the CMAPs before walking and immediately after onset of the intermittent claudication, and then continuously recorded them every few seconds.In all patients the latency of CMAPs showed no changes after walking stress. But in fifteen patients of twenty the amplitude decreased by various degrees immediately after walking stress and gardually made recovery to the control.The decreased amplitude of CMAPs was reflected the impairment of the motor axons.We conclude that the temporary conduction block of the cauda equina and/or lumbar nerve root occurs in the imtermittent claudicaion of the lumbar canal stenosis.

We present the techinque of simultaneous recording of bilateral spinal cord potentials by peripheral nerve stimulation using paired stimulation technique. The conditioning stimulus (S1) is applied to left median nerve and the test stimulus applied to right median nerve at a varing time interval after S1. Spinal cord potential is recorded from cervical epidural space. Subtracted response from evoked by bilateral median nerve stimulaion to only right median stimulation is equal to the response evoked by left median nerve stimulation from 0 to 40 msinterstimulous interval. This result showed that this method is useful to assess the bilateral spinal cord function indivisually moreover simultanously, and we emphasize that this method is useful for intraoperative monitoring.