Function and strength declines in a client with radiation-induced brachial plexopathy: a case report.

Introduction: Radiation-induced brachial plexopathy (RIBP) is a progressively disabling outcome of radiotherapy for a variety of cancers. This report describes measured declines over time in a client with very late RIBP, secondary to radiotherapy for breast cancer.

Case Description: After diagnosis of stage IIIA (right) breast cancer (age 50), this woman underwent bilateral mastectomy, chemotherapy and daily radiotherapy (25 sessions) to the right chest wall, supraclavicular and axillary lymph nodes. A neurological exam (age 72) showed diminished deep tendon reflexes in the right brachioradialis, biceps and triceps; nerve conduction tests revealed decreased amplitude of sensory and motor nerves in the right arm. Also, standardized measurements of grip and pinch strength were obtained by a hand therapist. The client was sent to a neurooncologist, who referred her to occupational therapists to update standardized assessments of grip/pinch strength and functional dexterity, as well as provide assistive technology and therapy suggestions.

Outcomes: Grip strength decreased 28.1%, with recent grip strength < 50% of the median normative value for the dominant hand. Lateral pinch strength dropped by 67%, now 16% of normal. Lateral key/three-point pinch strength decreased by 95%, now 2.3% of normal. Functional dexterity decreased also in the affected hand, with astereognosis noted.

Discussion: This is the first report describing increasing deficits in RIBP using standardized measures of grip and pinch strength, manual dexterity and stereognosis. Sadly, there is no successful intervention to increase muscle strength in RIBP which results in progressive strength loss, as shown with this client's hand strength over three years.