Tae Sung Park
Tae Sung Park and James M. Johnston
✓ Selective dorsal rhizotomy is a well-established surgical procedure for improving lower-extremity spasticity in children with cerebral palsy. The standard technique requires an L1–S1 laminectomy or laminoplasty for visualization of all dorsal nerve roots exiting at their respective foramina. The authors describe a rhizotomy procedure that requires a single-level laminectomy at the level of the conus, with the advantages of decreased operating time and postoperative pain as well as a minimal risk of progressive lumbar instability. This procedure is both effective and well tolerated in appropriately selected children and adults, and has had one cerebrospinal fluid lead requiring operative repair in more than 1500 patients treated at the authors' institution since 1991.
Michael S. Turner
Jack R. Engsberg and Tae Sung Park
Charles Kuntz IV, and Tae Sung Park
Tae Sung Park
Shenandoah Robinson, Bruce A. Kaufman, John A. Jane Jr. and Tae Sung Park
Jack R. Engsberg, Sandy A. Ross and Tae Sung Park
Object. In this investigation the authors quantified changes in ankle plantarflexor spasticity and strength following selective dorsal rhizotomy (SDR) and intensive physical therapy in patients with cerebral palsy (CP).
Methods. Twenty-five patients with cerebral palsy (CP group) and 12 able-bodied volunteers (AB controls) were tested with a dynamometer. For the spasticity measure, the dynamometer was used to measure the resistive torque of the plantarflexors during passive ankle dorsiflexion at five different speeds. Data were processed to yield a single value that simultaneously encompassed the three key elements associated with spasticity: velocity, resistance, and stretch. For the strength test, the dynamometer rotated the ankle from full dorsiflexion to full plantarflexion while a maximum concentric contraction of the plantarflexors was performed. Torque angle data were processed to include the work done by the patient or volunteer on the machine. Plantarflexor spasticity values for the CP group were significantly greater than similar values for the AB control group prior to surgery but not significantly different after surgery. Plantarflexor strength values of the CP group were significantly less than those of the AB control group pre- and postsurgery. Postsurgery strength values did not change relative to presurgery values.
Conclusions. The spasticity results of the present investigation agreed with those of previous studies indicating a reduction in spasticity for the CP group. The strength results did not agree with the findings of most previous related literature, which indicated that a decrease in strength should have occurred. The strength results agreed with a previous investigation in which knee flexor strength was objectively examined, indicating that strength did not decrease as a consequence of an SDR. The methods of this investigation could be used to improve SDR patient selection.
Tae Sung Park
Experience at the Hospital For Sick Children, Toronto, 1950–1980
Tae Sung Park, Harold J. Hoffman, E. Bruce Hendrick, Robin P. Humphreys and Laurence E. Becker
✓ The authors review the cases of 144 children with medulloblastoma treated between 1950 and 1980. Duration of time between onset of symptoms and initial treatment was less than 1½ months in 51% of cases, and less than 3 months in 76%. The tumor was located in the cerebellar vermis in 93% of patients. Brainstem infiltration was noted in 32%. Classical medulloblastomas comprised 82% of the total number reviewed, and desmoplastic medulloblastomas 15%. The majority of desmoplastic medulloblastomas were found in the midline of the cerebellum and in patients under 10 years of age. The prognosis for patients with desmoplastic medulloblastomas was worse than that for children with classical medulloblastomas. Spontaneous hemorrhage associated with primary or recurrent medulloblastoma occurred in 5.6% of the patients. Supratentorial metastases were found in 14.6% of cases, spinal cord metastases in 12.5%, and systemic metastases in 9%. The overall 5-year survival rate was 47%, and the 10-year survival rate 42%. Extent of surgical excision proved to be a statistically significant prognostic factor. Two patients developed recurrence after the “period of risk” as defined by Collins' rule. Delayed complications of radiotherapy were found to be substantial. Intelligence quotient (IQ) testing on 16 survivors revealed verbal IQ, performance IQ, and full-scale IQ to be within the normal range in 11, seven, and nine cases, respectively. Two were retarded on all scores.