Hyperreflexia means overresposive reflexes which could include twitching, suggest upper motor neuron disease, hypernatremia, stroke, brain tumor, spinal cord injury, etc. causes
of increased tone
of lower limbs are cervical spinal cord injury
or tumor, cervical spondylosis, multiple sclerosis, upper motor neuron disorder. Confide in your dad and help him by being around for his neurologist’s office visit. You are very welcome with any further posts on this forum. Take care.