Akito Hayashi

Disorder in reciprocal innervation upon initiation of voluntary movement in patients with Parkinson's disease

SummaryReciprocal innervation of the soleus motoneurones upon initiation of voluntary ankle dorsiflexion was investigated in eight patients with Parkinsons disease. H-reflex and visually guided step tracking methods were used for testing moto-neurone excitability and for controlling the timing of movement initiation, respectively. While reciprocal inhibition appeared almost simultaneously with the agonist electromyographic (EMG) onset in normal subjects (Kagamihara and Tanaka 1985), facilitation appeared in the majority of patients under the same onset condition. It increased slowly, reaching a maximum at about 100 ms after the EMG onset. It then subsided slowly at around 200–300 ms, and was replaced thereafter by an inhibitory effect. No coactivation of the soleus muscle was detected electromyographically. The facilitation between the EMG onset and the onset of mechanical contraction was attributed to the direct effect of the descending command from the brain, suggesting a certain disorder in controlling the system for reciprocal innervation.

Mechanism and treatment of dropped head syndrome associated with parkinsonism

Dropped head syndrome (DHS) associated with parkinsonism is not frequent, but it markedly reduces the activities of daily living and is refractory. To elucidate the mechanism and treatment of DHS associated with parkinsonism, we assessed 28 parkinsonian patients with DHS (2 men and 26 women) by examining their clinical features and cervical-muscle-needle and surface electromyographic (EMG) recordings. We also evaluated the effects of lidocaine, muscle afferent block (MAB; 1% lidocaine mixed with ethanol), and botulinum toxin injected into the bilateral sternocleidomastoid muscles (SCMs), which were considered to be the affected muscles. In some patients, DHS occurred after the initiation or loading of dopamine agonists (less common after pergolide than cabergoline and pramipexole). Improvement was noted after a reduction in the dopamine agonist dose in some patients, and loading of l-dopa in others. Needle EMG revealed no evidence for weakness of the dorsal neck muscles. Surface EMG showed a gradual increase in SCMs activity upon passive head lifting. Lidocaine injection into SCMs markedly improved DHS, but the effect was temporary. The effect of botulinum toxin and MAB was not satisfactory. Whereas DHS could have a heterogeneous etiology, dopamine receptor sensitivity may play a role in its pathogenesis. For the treatment of DHS in parkinsonian patients, an increase in the dosage of l-dopa and a decrease in that of the dopamine agonist should be considered. Lidocaine injection (lidocaine test) could be useful for determining the most affected muscle before using botulinum toxin or MAB. Further studies are needed to examine the outcome of such treatments that include GPi-DBS.

Reassessment of H‐reflex recovery curve using the double stimulation procedure

We conducted two types of experiments to assess the validity of the H‐reflex recovery test, using double stimulation to test soleus motoneuron pool excitability in healthy and spastic subjects. One type dealt with the mechanical effect of the conditioning H reflex on the ankle joint; the other type with the effect of change in reflex size. The mechanical effect was tested both with the ankle joint fixed (FX) and free to move (FR). Differences between FX and FR conditions commenced with relaxation of soleus muscle contraction by the conditioning H reflex. In the FR condition, abrupt facilitation occurred, and changed to marked depression. We conclude that specific facilitation and inhibition in the FR condition were secondary effects of group Ia inflows caused by the ankle extensor muscle stretching on relaxation. In some spastic patients as well as in controls, facilitation due to the mechanical effect in the FR condition was observed despite the FX condition. The effects of systematic changes on soleus H‐reflex size were investigated at conditioning–test intervals of 80 ms, so as to avoid mechanical effects. When conditioning and test reflexes were the same size, the amount of recovery increased as the H‐reflex size increased. Comparison of the relation between amount of recovery and H‐reflex size, expressed as a percentage of Mmax, showed no significant difference between the two groups. We speculate that the stronger recovery of spasticity mentioned in previous literature may have resulted from the fact that relatively greater H reflexes were tested in those studies. In conclusion, the present study indicates that double stimulation is not appropriate for assessing spinal motoneuron pool “excitability increase” in spasticity.

Successful immune moderation treatment for progressive encephalomyelitis with rigidity and myoclonus.

Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a rare disease. PERM consists of the same symptoms as stiff person syndrome, in addition to sensory, brainstem and autonomic features. We herein report a case of PERM in a 48-year-old woman who initially presented with spasticity of the lower limbs and subsequently developed upper limb spasticity, perioral myoclonus and restlessness after three months. The onset of potentially fatal dysautonomia was observed at the peak of the disease. Treatment with high-dose immunoglobulin (400 mg/kg, 5 days), levetiracetam and azathioprine resulted in a drastic and sustained improvement of these symptoms. This is an interesting case of PERM in which the patient showed a dramatic improvement following immune moderation.

EFFECT OF AGE, GENDER, AND WALKWAY LENGTH ON ACCELEROMETRY-BASED GAIT PARAMETERS FOR HEALTHY ADULT SUBJECTS

Accelerometry is now a well-established method for monitoring human body movements, and is increasingly being used for gait analysis under nonlaboratory conditions because of its low-cost and unobtrusive nature. In order to encourage its use in the clinical setting such as for assessing functional declines due to aging or disease, an extensive database of healthy gait is needed. This paper presents reference data for 245 normal Japanese adults (126 men and 119 women aged 40–86 years) obtained from indoor walk tests by using a trunk-mounted acceleration sensor. Seven gait parameters were extracted from the acceleration data measured at fast, normal, and slow gait for 5m and 10m walkways. The effects of age on cadence, speed, and step length were consistent with those observed in previous studies. Scaled speed and acceleration were closely correlated with each other, and exhibited similar gender- and age-associated behavior, indicating that they could be used interchangeably in gait analysis. A comparison o...

Pilot Study of a Device to Induce the Hanger Reflex in Patients with Cervical Dystonia

The hanger reflex (HR) is an involuntary head rotation that occurs in response to a clothes hanger encircling the head and compressing the unilateral fronto-temporal area. Here, we developed an elliptical device to induce the HR and examined its utility for the treatment of cervical dystonia (CD). The study included 19 patients with rotational-type CD. The device was applied to each subject’s head for at least 30 min/day for 3 months. Severity scores on part 1 of the Toronto Western Spasmodic Torticollis Rating Scale were evaluated at baseline and after the 3-month trial. Mean scores without and with the device were significantly different both at baseline (16.6 vs. 14.7, respectively; P < 0.05) and after the trial (14.9 vs. 13.6, respectively; P < 0.05). This preliminary trial suggests that our device can improve abnormal head rotation in patients with CD.

Early clinical evaluation of total hip arthroplasty by three-dimensional gait analysis and muscle strength testing

BACKGROUND As improvement of gait is an important reason for patients to undergo total hip arthroplasty (THA) and they generally tend to evaluate its success based on postoperative walking ability, objective functional evaluation of postoperative gait is important. However, the patients normal gait before osteoarthritis is unknown and the changes that will occur postoperatively are unclear. We investigated the change in gait and hip joint muscle strength after THA by using a portable gait rhythmograph (PGR) and muscle strength measuring device. PATIENT AND METHODS The subjects were 46 women (mean age: 65.9 years) with osteoarthritis of the hip. Gait analysis and muscle strength testing were performed before THA, as well as 3 weeks and 3 months after surgery. We measured the walking speed, step length, and gait trajectory using PGR prospectively. PGR is attached to the patients waist and records signals at a sampling rate of 100 Hz. Isometric torque of hip flexion and abduction were measured by using a hand-held dynamometer. RESULTS There was no improvement at 3 weeks postoperatively, but the walking speed, stride length and muscle strength were clearly showed improvement at 3 months postoperatively. The walking trajectory was not normal preoperatively, since the trajectory was not symmetrical and did not intersect in the midline or form a butterfly pattern, and abnormality of the trajectory tended to persist postoperative 3 months despite resolution of hip joint pain after surgery. CONCLUSION Since postoperative improvement of gait is an important consideration for patients undergoing THA, it seems relevant to evaluate changes in the gait after surgery and three-dimensional analysis with a PGR may be useful for this purpose.

White matter lesions and cognitive impairment may be related to recovery from unilateral spatial neglect after stroke

BACKGROUND Unilateral spatial neglect (USN) is frequently found in ischemic stroke patients. Because USN is related to poor functional outcomes, evaluating recovery from USN after stroke is critical. METHODS Patients with acute ischemic stroke with lesions in the right cerebral hemisphere on MRI and exhibiting left USN were administered the Behavior Inattention Test (BIT) at 1 and 3weeks after admission. BIT improvement was defined as a ≥1-point increase in ≥4 of the 6 BIT subtests from 1 to 3weeks, or a total BIT score ≥131 at 3weeks. Factors associated with improvement of left USN were analyzed. RESULTS Eighteen patients (8 men; mean age, 70±12years) were enrolled in this study. BIT was performed at 5.3±0.7 and 18.2±0.7days after admission. Twelve patients were classified to the improvement (I) group, and 6 to the non-improvement (NI) group. BIT scores increased substantially from 76.6±40.5 in the acute phase to 109.2±43.3 in the subacute phase. The I group displayed higher BIT scores than the NI group in both acute and subacute phases (P<0.01 each). The degree of white matter lesions on the Fazekas scale was lower in the I group (0.6±0.7) than in the NI group (1.7±1.2, P=0.028). Increased BIT scores correlated significantly with increased Mini Mental State Examination scores (r=0.487, P=0.040). CONCLUSIONS Amelioration of left USN might be related to white matter lesions and cognitive impairment. Sample size in the current study was small, limiting the generalizability of results, and larger studies are warranted in the future.