Clinical features of conus medullaris are all EXCEPT:
Late bladder involvement REF: Principles of surgical patient care 2nd/501, De Jong's Neurological examination 6' ed p. 578, neurological examination by Schwazman Conus medullary lesions are associated with absent ankle jerks alone. Knee jerks (patellar reflex)) is not absent Features Conus medullaris Cauda equina Site of injury Sacral spinal cord (conus) & lumbosacral nerve roots Lumbosacral nerve roots ( alone ) Nature of lesions (UMN/LMN) UMN + LMN LMN Babinski Extensor /positive Flexor/negative Tendon reflexes Only ankle reflex is absent (knee reflex may be exaggerate) Both ankle and knee reflex may be absent Pain (spontaneous) * Minimal * Not common or severe * Bilateral and symmetrical in perineum or thighs * Significant * May be the most prominent symptoms. * In perineum , thighs , legs or back, distribution of sacral nerves * Radicular in type Sensory defect * Saddle distribution * Bilateral usually symmetric * Dissociation of sensation may be seen * Saddle distribution * May be unilateral and symmetric * No dissociation of sensation Motor loss * Symmetric * Not marked * Fasciculation may be present * Atrophy may occur * Asymmetric * More marked * Usually no Fasciculation * Atrophy may occur Bladder and rectal examination * Early and marked * Late and less marked Trophic changes * Decubiti common * Decubiti less marked Sexual functions * Erection and ejaculation impaired * Less marked impairment Onset * Sudden and bilateral * Gradual and unilateral
Late bladder involvement
Extensor plantar
Sacral anesthesia
Lower sacral and coccygeal involvement