CACNA1A and Rare hereditary ataxia: • Serological tests (blood count, electrolytes, liver and bone profile, thyroid function, vitamin B1, vitamin B12, vitamin E, autoimmune profile, paraneoplastic panel)• Genetic tests (SCA panel, RFC1, EA2, FXN, WGS [if available])• MRI brain• Cerebrospinal fluid examination (autoimmune/inflammatory)• Nerve conduction study (hereditary ataxias with neuropathy)• PET scan (for suspected paraneoplastic syndrome)• Hearing assessment (pure-tone audiometry, brainstem responses)• Vestibular assessment (vHIT, caloric test, rotatory chair, VEMP)