Neurological Conditions Flashcards
Lumbar Disc Herniation . Epidemiology
Most common ages 30 to 50 years
Rarely occurs before age 20 years
Most common spinal levels affected (95% of lumbar disc)
Vertebral level L4-5
Vertebral level L5-S1
Lumbar Disc Herniation - Mechanism
Progressive degeneration of disc nucleus pulposus
Results from normal aging or repetitive Trauma
Protrusion of disc (most commonly posterior-lateral)
Herniation affects spinal root one level below
Other Changes: Spondylosis (Chronic disc deterioration) Spur Formation Disc space narrowing Facet joint degeneration
Lumbar Disc Herniation - Symptoms
Usually insidious onset
Acute Trauma may have preceded symptoms
Low Back Pain (deep aching)
Aggravated by activity, coughing, and sneezing
Relieved by rest
Localized to affected disc
Intense Radicular Pain
Referred pain to iliac crest or buttock Radiation of pain down posterior thigh and calf Pain may radiate into foot Paresthesias Numbness or tingling in distal extremity
C Spine Herniation - Epidemiology
Incidence (U.S.)
Men: 107 per 100,000/year
Women: 64 per 100,000/year
C5-C6 disc represents 90% of cervical disc lesions
C6 nerve root impingement is most common (followed by C7 nerve root impingement)
C Spine Herniation - Anatomy
Cervical spinal nerves C1-C7 exit about their corresponding Vertebrae
In transitioning to Thoracic Spine, C8 exits below the C7 Vertebra, and above T1
In contrast, all thoracic and lumbar spinal nerves exit below their corresponding Vertebrae
Lateral Herniation compresses the nerve root below
Example: C5-6 disc Herniation compresses C6 root
C Spine Herniation - types of nerve impingement
Acute Cervical Disc Herniation (younger patients, accounts for 22% of radiculopathy cases overall)
Soft disc protrusion from nuclear Herniation
Intraforaminal disc Herniation causes sensory radiculopathy (most common)
Posterolateral disc Herniation causes weakness and muscle atrophy
Central DIsc Herniation causes central cord compression and myelopathy (least common)
May result in numbness and weakness as well as Ataxia, urine changes
Chronic Cervical Disc Disease (older patients, majority of patients)
See Cervical Spine Anatomy
Cervical Spine degeneration associated with Osteoarthritis
Spurring at uncovertebral joint (posterior foramen) compresses Sensory Nerve roots
Spurring at facet joints (anterior foramen) compresses Motor Nerve roots
Hard disc lesion associated with Cervical Spondylosis
C Spine Herniation - Symptoms
Weakness (15% of patients) Radiation into Shoulder Radiation along Radial Nerve distribution into arm Does not often radiate below elbow Contrast with Paresthesias (distal radiation) Radiation into medial Scapula Interscapular pain is not of Shoulder origin Provocative Worse with activity Worse on awakening in Morning Worse with neck extension Worse with coughing, sneezing, or straining Associated symptoms Headaches Dysphagia Related to large anterior osteophytes
Thoracic Outlet Syndrome - symptoms
Neural Involvement Extremity pain Extremity numbness Arterial Involvement Extremity falls asleep Glove distribution with or without paresis Venous Involvement Distal extremity swelling
Thoracic Outlet Syndrome - exam
Sensory and Motor Exam
Specific provocative maneuvers
Adson’s Test
Costoclavicular Maneuver GH extension with depression of scapula
Wright’s Test - abduction
Elevated Arm Stress Test (Roos Stress Test, EAST Test)
Lower motor neuron lesion - One major characteristic used to identify a lower motor neuron lesion is
flaccid paralysis – paralysis accompanied by loss of muscle tone. This is in contrast to an upper motor neuron lesion, which often presents with spastic paralysis – paralysis accompanied by severe hypertonia.
Lower motor neuron lesion Signs and symptoms
Muscle paresis or paralysis
Fibrillations
Fasciculations – caused by increased receptor concentration on muscles to compensate for lack of innervation.
Hypotonia or atonia – Tone is not velocity dependent.
Hyporeflexia – Along with deep reflexes even cutaneous reflexes are also decreased or absent
Strength – weakness is limited to segmental or focal pattern, Root innervated pattern
The extensor Babinski reflex is usually absent. Muscle paresis/paralysis, hypotonia/atonia, and hyporeflexia/areflexia are usually seen immediately following an insult. Muscle wasting, fasciculations and fibrillations are typically signs of end-stage muscle denervation and are seen over a longer time period. Another feature is the segmentation of symptoms – only muscles innervated by the damaged nerves will be symptomatic.
Lower motor neuron lesion Cause
Most common causes of lower motor neuron injuries are trauma to peripheral nerves that serve the axons – a virus that selectively attacks ventral horn cells.
Disuse atrophy of the muscle occurs i.e., shrinkage of muscle fibre finally replaced by fibrous tissue (fibrous muscle)
Other causes include Guillain–Barré syndrome, C. botulism, polio, and cauda equina syndrome; another common cause of lower motor neuron degeneration is amyotrophic lateral sclerosis.
Upper motor neuron - lesions occur in the brain or the spinal cord as the result of-
stroke, multiple sclerosis, traumatic brain injury and cerebral palsy.
Upper motor neuron Symptoms
Muscle weakness.[2] known as ‘pyramidal weakness’
Decreased control of active movement, particularly slowness
Spasticity, a velocity-dependent change in muscle tone
Clasp-knife response where initial higher resistance to movement is followed by a lesser resistance
Babinski sign is present, where the big toe is raised (extended) rather than curled downwards (flexed) upon appropriate stimulation of the sole of the foot. The presence of the Babinski sign is an abnormal response in adulthood. Normally, during the plantar reflex, it causes plantar flexion and the adduction of the toes. In Babinski’s sign, there is dorsiflexion of the big toe and abduction of the other toes. Physiologically, it is normally present in infants from birth to 12 months. The presence of the Babinski sign after 12 months is the sign of a non-specific upper motor neuron lesion.
Increased deep tendon reflex (DTR)
Pronator drift [3]
