Hereditary Spastic Paraplegia

Diagnosis

The diagnosis of hereditary spastic paraplegia (HSP) is typically based upon a careful patient and family history, a thorough clinical evaluation, and assessment of characteristic symptoms and findings (e.g., weakness, rigidity, and spasticity of lower limbs; associated gait disturbances due to difficulties with upward bending [dorsiflexion] of the foot and flexion of the hip; diminished vibration sense in the feet; etc.). Diagnostic evaluation may also include various specialized tests. (See below.)

Although analysis of DNA extracted from blood samples may assist in diagnosing certain forms of HSP (e.g., due to known gene mutations in certain families), such testing is not widely available. As more is learned about the different genetic causes of HSP, it is hoped that such information will lead to additional laboratory studies (and greater availability of such testing) to help confirm the diagnosis. Thus, in most instances, there is currently no definitive test for HSP. Rather, if patients have characteristic symptoms of HSP—and others in their families have had similar features—such findings may suggest a possible diagnosis of HSP. Diagnostic evaluation may include specialized tests to detect or characterize certain findings that may be associated with the disorder. Studies will also be conducted to help rule out or detect other disorders with similar symptoms, particularly if a family history of HSP is not present or is questionable. In those with certain, additional neurologic features, testing may also be required to confirm or eliminate other neurologic diseases or to verify the possible co-existence of HSP with such a condition. (For further information, see the section entitled "Symptoms/Findings/Disorder Classification."

[Patients should note that spastic paraplegia may also occur as a secondary condition—as opposed to a primary finding due to the genetic abnormalities seen in HSP. In other words, spastic paraplegia may also result from various underlying disorders or other factors, such as spinal cord trauma or neoplasms; certain viral diseases, such as tropical spastic paraparesis (HTLV-1-associated myelopathy); multiple sclerosis (MS); or other disorders. Therefore, the differential diagnosis of HSP may include certain tests to help eliminate such conditions.

In those with suspected HSP, recommended diagnostic studies may include...

• Certain blood tests and other laboratory studies
• Reflex studies to detect abnormal reflex responses of the lower limbs
• Electrophysiologic studies, such as electromyography (EMG), nerve conduction tests, or electroencephalography (EEG)
• Neuroimaging studies, including computerized tomography (CT) scanning or magnetic resonance imaging (MRI), to create detailed, cross-sectional images of the brain and spinal cord
• Lumbar puncture (hollow needle is inserted between two bones of the vertebral or spinal column and then CNS fluid is withdrawn)
• Other tests to help confirm HSP or to verify or eliminate other disorders