Spinal Cord Diseases Flashcards
Corticospinal tracts:
control muscle strength, tone and reflexes
Dorsal columns:
Vibration and position sense (proprioception)
Anterolateral spinothalamtic tracts:
conduct Pain and Temperature
Motor neurons are in the __ and lesion there cause __.
Anterior horns.
Weakness and atrophy.
Decreased/absent reflexes are at the __ of the lesion and reflexes ___ below the lesion.
Level of lesion.
Increased below lesion.
Dermatome level at umbilicus:
T10
Dermatome level at nipples:
T4 (5)
Dermatome level at thumb/fingers1,2:
C6
Dermatome level at finger 3:
C7
Dermatome level at fingers 4,5:
C8
Achilles reflex at spinal levels:
S1-2
“1,2 buckle my shoe”
Patellar reflex at spinal levels:
L3-4
“3,4 Kick the door”
Biceps and brachioradialis reflexes at spinal levels:
C5-6
“5,6 pick up sticks”
Triceps reflex at spinal levels:
C7-8
“7,8 lay them straight”
Cord ends at __ vertebral level, spinal canal below this level contains nerve roots (cauda equina)
L1
Anterior spinal artery supplies:
Anterior 2/3 of cord: anterior horns, spinothalamic tracts, corticospinal tracts
Posterior spinal artery supplies:
Posterior 1/3 of cord: Dorsal column and dorsal horns.
Segmental arteries from the aorta:
Anastomoses with spinal arteries. Example - artery of Adamkiewcz
artery of Adamkiewicz:
at T10, major source of blood for lower cord.
Brown-Sequard Syndrome = hemicord, sings:
- Ipsilateral Corticospinal tract signs and ipsilateral Dorsal column signs (fibers cross in medulla)
- Contralateral Spinothalamic tract (fibers cross below lesion and 1-2 segments above)
- a unilateral focal lesion (tumor, trauma)
Lhermitte sign:
Electric-like sensation extending down back and/or into arms with neck flexion.
Seen with focal cervical lesions, most notably demyelinating lesions.
Meningeal irritation:
With meningitis or subarachnoid hemorrhage:
Nuchal rigidity,
Kernig sign,
Brudzinski sign.
Nuchal rigidity:
painful inability to flex neck
Kernig sign:
painful knee extension/resistance with hips and knees flexed 90 degrees
Brudzinski sign:
involuntary lifting of legs with neck flexion in spine position.
Potential causes of acute extradural:
Trauma: MVA, motorcycle, sports injuries; falls in elderly—symptoms often due to fracture, infarct, hematoma.
Metastatic cancer to vertebrae: breast, lung, prostate, kidney, colon, myeloma.
Lymphoma
Abscess
Disc herniation affecting cord
AVM
Hematoma
Acute Intradural/Extramedullary causes:
Primary tumor e.g. meningioma.
Meningitis with arteritis
Acute Intradural/Intramedullary causes:
Inflammatory Transverse myelitis Multiple sclerosis Neuromyelitis optica (NMO) SLE Sjögren syndrome Sarcoidosis Vascular Infarction: arteriosclerotic versus arteritis versus aortic dissection (especially at T10—artery of Adamkiewicz) Infectious HTLV1 HIV Syphilis Tuberculosis Bacterial, viral and fungal lesions Trauma: Hematomyelia Anterior Spinal Artery Syndrome. Posterior spinal artery syndrome.
Acute Spinal Artery Syndrome:
Acute onset with initial flaccid paraplegia or quadriplegia depending on location of artery occlusion.
Followed by the flaccidity, converting to spasticity with increased reflexes and Babinski signs.
Sensory loss, with loss of pain and temperature and sparing of vibration, position sense, and partially touch. (i.e. Spare the Dorsal Columns)
Bladder and bowel function are impaired.
Posterior Spinal Artery Syndrome:
Rare, and involving posterior column dysfunction and bladder and bowel symptoms.
Chronic extradural causes:
Disc/osteophyte complex with chronic disc herniation and epidural extension.
Primary bone tumors e.g. chondrosarcoma, osteogenic sarcoma
Lymphoma.
Dural AVM (occasionally intramedullary) and dural AV fistula.
Lipoma.
Miscellaneous e.g. rheumatoid arthritis, Paget disease, Pott disease (TB)
Chronic Intradural Extramedullary causes:
Meningioma, schwannoma, neurofibroma, AVM
Chronic Intradural Intramedullary:
Syringomyelia. Subacute combined degeneration. Hereditary spastic paraparesis. Friedreich ataxia. Amyotrophic lateral sclerosis (ALS). HTLV-1 myelopathy. AIDS associated vacuolar myelopathy. Poliomyelitis
Syringomyelia:
Cavity within cord, at times associated with Chiari 1 malformation. Often in cervical area.
Classically, presents with pain and temperature loss in cape distribution, weakness/atrophy in arms, and, ultimately, corticospinal and dorsal column dysfunction below syrinx.
Subacute combined degeneration:
Progressive involvement of corticospinal tracts and dorsal columns with increased reflexes, Babinski signs, and loss of position and vibration. A polyneuropathy is also often present.
Three most common causes are:
1. Vitamin B12 deficiency—pernicious anemia and post gastric surgery
2. Copper deficiency—post gastric surgery or excessive zinc ingestion (e.g. zinc containing dental paste) which impedes copper absorption.
3. Vitamin E deficiency—post small bowel surgery, cystic fibrosis, abetalipoproteinemia
Hereditary spastic paraparesis:
Degeneration of distal corticospinal axons and dorsal column degeneration and manifested primarily by slowly progressive spastic paraparesis. Patients have spasticity, hyperactive reflexes and Babinski signs. May be inherited in autosomal dominant or recessive or X-linked fashion due to multiple potential gene abnormalities. Age of onset is variable.
Friedreich Ataxia:
Autosomal recessive disorder (trinucleotide repeat expansion of the frataxin gene) causing degeneration of the dorsal columns, lateral corticospinal tract signs, spinocerebellar tracts, dorsal roots and ganglia, and peripheral nerves.
Onset is usually in childhood or adolescence and manifested by ataxia, sensory loss, dysarthria, areflexia, and Babinski signs.
ALS:
Progressive disorder of upper and lower motor neurons usually beginning in adulthood and occurring sporadically most of the time but is familial in 10% of cases. It is associated with a variety of genetic abnormalities the most common of which is hexanucleotide repeat expansion of c9orf72. A merciless disease for which there is no specific treatment, life expectancy averages 5 years. Clinical features include muscle wasting and weakness beginning in the extremities or bulbar muscles, fasciculations, cramps, hyperactive reflexes, Babinski signs. As weakness progresses, reflexes may be lost. Difficulties swallowing and breathing are often late events requiring a feeding tube and respiratory assistance. Associated clinical features in a minority of patients include frontotemporal dementia and Parkinson disease.
HTLV-1 Myelopathy
Progressive spastic paraparesis due to the transmission of a Type C oncovirus by semen, blood, breast milk and shared needles. It is endemic in the Caribbean and South America.
AIDS associated vacuolar myelopathy
Late in the course of the systemic illness.
Major symptoms are spastic paraparesis, weakness, painless vibratory and position sense loss and sensory ataxia.
Poliomyelitis:
Acute inflammatory illness affecting the motor neurons in the anterior horns.
This illness, caused by the poliovirus and characterized by flaccid weakness, has been largely eradicated but the syndrome can be caused by other enteroviruses and West Nile virus.
