Primary progressive multiple sclerosis (PPMS) is an uncommon form of MS that affects approximately 10-15% of MS patients. In PPMS, symptoms steadily get worse over time without frequent relapses or remission.
Unlike relapse-remitting MS (RRMS), which affects women more than men, PPMS affects an equal number of both genders. PPMS is usually diagnosed in older individuals between the ages of 40 to 60, yet it is sometimes diagnosed beyond this range.
Early symptoms in PPMS develop slowly over a period of time and usually involve issues with walking and general mobility. The pace and progress of PPMS can vary from patient to patient. In some people with PPMS, relapses can occur along with steady disease progression. This is referred to as progressive-relapsing MS (PRMS).
Diagnosis of PPMS
The diagnosis of PPMS is particularly difficult as it is diagnosed in the 40s and 50s when other health issues related to mobility tend to develop. Since PPMS is characterized by a gradual and steady accumulation of disability over time, the criteria for diagnosis of PPMS are different from that of other forms of MS.
The criteria include:
- Steady disease progression
- Worsening of neurological function for one year without remission
- Brain lesions typical of MS
- Multiple lesions in the spinal cord
- Indications of immune activity in the CNS (such as elevated IgG index)
These criteria often take a long time to develop, hence PPMS diagnosis usually taking two to three years more than diagnosis of RRMS.
Management of PPMS
Treatment for PPMS mainly aims at managing neurological symptoms. Ongoing drug trials focus on reducing relapses and slowing down the disease progression rate as well as the build-up of disability.
Currently, no FDA-approved medications are available for the treatment of PPMS. This is mainly because most approved therapies work towards reducing inflammation, which is not a characteristic of PPMS. Many clinical trials are underway to find an effective drug for this disease.
Wellbeing and rehabilitation of people affected with PPMS is important and can be achieved by following a healthy diet and exercise regimen. Unsteadiness in walking and muscle weakness can be tackled with the help of an occupational therapist and a physiotherapist, while a dietician can help develop an appropriate meal plan based on the patient’s individual mobility levels.
Modifiers in PPMS
Neurologic examination and magnetic resonance imaging (MRI) must be performed at least once a year to evaluate disease progression and activity. Characterizing the disease course at regular intervals is important as it helps in updating treatment methods.
- If PPMS is active with relapses or fresh MRI activity, a disease-modifying therapy (DMT) should be started so as to mitigate the risk of an attack.
- If PPMS is stable with no progression or activity, treatment should focus on rehabilitation so as to maintain function and symptom management.
- If PPMS is inactive with no relapses or activity, but with disease progression and build-up of disability, treatment should aim at maintaining function and promoting independence of the patient.
- PPMS does not involve relapses due to inflammation; hence, patients with this type of MS have fewer lesions or plaques in the brain with fewer inflammatory cells.
- Relapsing forms such as RRMS and secondary progressive MS (SPMS) are characterized by frequent inflammatory attacks.
- The age of onset for relapsing forms of MS is about 10 years earlier than that for PPMS.
- PPMS tends to affect walking and mobility more than other functions, while relapsing MS types cause numbness, spasticity, vision problems, and cognitive decline.