Motor weakness in palliative care
Motor weakness (objective finding that muscles have reduced power) and lassitude (feeling weaker) can co-exist and are both common in patients with palliative care needs. Lassitude often has implications for comfortable physical function, and is a common contributor to fatigue in patients with palliative care needs; it may present without objective motor weakness. Causes of lassitude include cachexia and frailty.
Causes of true motor weakness in patients with palliative care needs include:
- cancer and its treatment (eg cancer-related cachexia–anorexia syndrome, local effects of tumour(s) [eg plexopathy, paraneoplastic syndromes, leptomeningeal disease]
- central or peripheral neurological syndromes (eg stroke, motor neurone disease, multiple sclerosis, peripheral neuropathy)
- myopathy.
Urgently assess for spinal cord compression in patients with cancer who present with back pain, or lower limb weakness with sphincter dysfunction. Spinal cord compression is a medical emergency; prompt action can significantly limit loss of function and maintain quality of life. See Malignant spinal cord compression in palliative care for management advice.
Management of motor weakness depends on the cause(s), potential benefits and burdens of treatment, and the patient’s prognosis, extent of disability, prognosis, preferences, and goals of care—see Principles of symptom management in palliative care. Management may focus on reversing motor weakness, limiting associated symptoms, achieving rehabilitation goals, or minimising further loss of function. Patients may benefit from multidisciplinary input, including from a palliative care team, primary healthcare team, physiotherapist, occupational therapist, and others as required and appropriate.
For motor weakness associated with cancer, management may involve local radiotherapy, chemotherapy or corticosteroids.