Which of the following is NOT listed as a nervous system impairment in spina bifida?

• A. Sensation
• B. Muscle tone
• C. Cranial nerves
• D. Hearing loss

Answer: (D)

When thinking about nervous system involvement in spina bifida, the focus is on how the spinal cord and nerve roots are affected. The defect disrupts sensory and motor pathways below the lesion, so you commonly see changes in sensation and in muscle tone. Sensation can be altered because the sensory nerves emerging from the affected spinal levels may not transmit signals normally. Muscle tone changes occur because the motor pathways to the limbs can be impaired, leading to hypo- or hypertonia depending on the level and severity of the defect. In some cases, spina bifida is associated with brainstem or hindbrain abnormalities like Chiari II malformation, which can affect cranial nerves, so cranial nerve involvement may occur in that broader context. Hearing loss, on the other hand, isn’t a typical nervous system impairment described as part of spina bifida’s neurologic profile; it concerns the auditory system and isn’t a direct consequence of the spinal defect unless there’s an unrelated or coexisting condition. Therefore, hearing loss is not listed as a nervous system impairment in spina bifida.