Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026827 (hypotonia)
 5,860 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rats with a right hemicerebellectomy (HCb) performed in adulthood or at weaning were compared behaviourally to rats with a similar lesion performed on the first postnatal day. The age at which animals received cerebellar lesions made a significant difference with respect to the behavioural outcome in adulthood. Posture, locomotion and motor behaviour were analysed by a battery of sensorimotor tests. Behavioural measurements showed a clear relationship between age at surgery and behavioural effects; rats with neonatal cerebellar lesions showed a slight extensor hypotonia contralateral to the lesion side and efficient locomotor activity, while the adult operated group exhibited a severe extensor hypotonia ipsilateral to the lesion side and hampered locomotion characterized by a wide base and ataxia. Weanling operated rats displayed a symptomatology similar to that observed in adult operates, although less severe. In the postural dynamic adjustments which the sensorimotor tests required, the youngest operated animals obtained higher scores in comparison to the other two experimental groups, except for the lack of hindlimb usage in the suspension on a wire test. These results, which show the importance of the age-at-lesion factor for the recovery of motor function after HCb in the rat, are discussed in the light of the widespread anatomical reorganization already demonstrated following neonatal HCb in rats.
 ...
PMID:Hemicerebellectomy and motor behaviour in rats. II. Effects of cerebellar lesion performed at different developmental stages. 229 69

Selective posterior rhizotomy is effective for relieving spasticity associated with cerebral palsy. In current techniques dorsal roots from L1/L2 to S1/S2 are selectively divided. With transoperative electromyography (EMG) significant sensory loss has been prevented, but postoperative hypotonia following excessive reduction of the fusimotor drive is still of concern for surgeons and therapists. To decrease the volume of deafferentiated rootlets we proposed a limited selective posterior rhizotomy (LPSR) that limits the extent of the surgery to three (L4-S1) or two (L5-S1) dorsal roots. We present the results of two group of spastic children; group 1 (n = 59, 32 quadriplegic and 27 diplegic) who had a L4-S1 LPSR, and group 2 (n = 12) in whom L5 and S1 were selectively rhizotomized. Posture, passive movilization, range of joint movement, and muscle tone in hip flexors, adductors, leg flexors and plantar flexors were graded according to the method proposed by Sindou and Jeanmonod. In all groups these was a significant reduction of the mentioned parameters (Friedman test p < 0.001) at 6, 12 and 18 months after surgery. The preoperative and postoperative ability to ambulate was classified into five grades. In all groups there was a significant (chi 2 between p < 0.01 and p < 0.001) improvement in the quality of their gait. A third of the patients achieved some form of independent ambulation. Our results suggest that extensive selective deafferentation of the lower limbs is not an absolute requisite for reducing muscle tone or achieving functional improvement in spastic children.
 ...
PMID:Limited (L4-S1, L5-S1) selective dorsal rhizotomy for reducing spasticity in cerebral palsy. 1048 86

Hypotonia, ligament laxity and motor alterations are characteristic for patients with Down syndrome (DS). The purpose of this study was the evaluation of typical gait pattern of subjects with Down syndrome and the quantification of their joint stiffness, connected with ligament laxity and hypotonia, as a possible compensation. 98 children with DS (mean age: 11.7 years; range: 6-15 years) and 30 healthy children (control group (CG); mean age: 11 years; range: 5-13 years) underwent full 3D gait analysis at self-selected speed. Subjects with DS walked with more hip flexion during the whole gait cycle, knee flexion in stance phase, a limitation of the knee range of motion, and plantarflexion of the ankle at initial contact. Ankle power was limited as evident in terminal stance and pre-swing, represented by a low propulsive capacity at push-off, too. Hip joint stiffness was increased in general in patients with DS versus normal subjects while ankle joint stiffness revealed a lower value instead.
Gait Posture 2008 Oct
PMID:Joint stiffness and gait pattern evaluation in children with Down syndrome. 1845 22

The inherent joint laxity and muscle hypotonia of adults with Down syndrome (DS) may result in reduced gait stability and increased energetic cost. These factors vary as a function of walking speed and may be reflected in gait patterns. The present study therefore examined whether the three-dimensional motion of the body center of mass (COM) and stepping characteristics differ between adults with and without DS as a function of speed. Fifteen adults with DS and 15 adults without DS underwent a series of treadmill walking trials. Walking speeds were determined as Froude numbers, based on leg length. Participants walked at Froude numbers of 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, and, for adults without DS, 0.7. Whole-body kinematic data were collected for 30-35 steps at each speed. Across speeds, adults with DS showed greater and more variable mediolateral COM motion than adults without DS. COM anteroposterior velocity and vertical motion did not differ in range between groups, but were more variable in adults with DS. Adults with DS also showed smaller-duration steps and varied their step widths and step lengths more than adults without DS. The results suggest a gait pattern with lesser stability and greater energetic cost among adults with DS.
Gait Posture 2009 Oct
PMID:Effects of Down syndrome on three-dimensional motion during walking at different speeds. 1959 93