Spinal Muscular Atrophy III (Kugelberg-Weilander Syndrome)
In more chronic SMA III, also referred to as Kugelberg- Welander syndrome, weakness usually initially occurs between the ages of 18 months and late teens. Motor milestones may be delayed in infancy.
Proximal weakness is observed, with the pelvic girdle being more affected than the shoulder girdle (57). There is an exaggerated lumbar lordosis and anterior pelvic tilt owing to hip extensor weakness. There is also a waddling gait pattern with pelvic drop and lateral trunk lean over the stance-phase side, secondary to hip abductor weakness. If ankle plantar flexion strength is sufficient, the patients may show primarily forefoot or toe contact and no heel strike similar to patients with Duchenne dystrophy. This is a compensatory measure for knee extensor weakness to maintain a stabilizing knee extension moment at the knee. The patient may exhibit a Gower's sign when arising from the floor; stair climbing is difficult due to hip flexor weakness. Facial weakness is sometimes noted. Fasciculations are noted in about half of the patients (97) and are more common later in the disease course. Fasciculations in the limb muscles and thoracic wall muscles are common. Calf pseudohypertrophy has been occasionally noted, but wasting of affected musculature is more prominent. Deep tendon reflexes are diminished and often become absent over time. Contractures are generally mild as long as patients remain ambulatory. Scoliosis may be observed in SMA III, but it occurs less frequently and is less severe than scoliosis and SMA II. While no survival data exist for patients with SMA III, cases have been followed into the eighth decade without mechanical ventilation (57,98). Ventilatory failure due to neuromuscular restrictive lung disease is a rare event in SMA III, occurring only in adulthood (57,117).Zerres and Rudnik-Schoneborn (98) have proposed further subtypes, including SMA IIIa (walks without support; age of onset less than 3 years) and SMA IIIb (walks without support; age of onset 3-30 years). In their series, only 44% of SMA “Illa” patients remained ambulatory 20 years after onset of weakness, whereas 89% of “IIIb” patients remained ambulatory after a similar 20-year duration.
More medical literature on Medic.Studio
More on the topic Spinal Muscular Atrophy III (Kugelberg-Weilander Syndrome):
-
Infectious diseases -
Internal diseases -
Obstetrics and Gynaecology -
Pediatrics -
Veterinary medicine -
-
Conflictology -
Ecology -
Economy -
Finance -
History -
Law -
Medicine -
Philosophy -
Religious studies -