Neurology is a very in course and today, I will be focusing on the Pathological aspect of Neurology (Neuro Pathology), and I will write about Spinal cord lesions. In simple words, Spinal Cord lesion is a neurological condition involving an injury or damage to the spinal cord. In this post, I will be discussing partial spinal cord lesions and complete spinal cord lesions. So let us start with the incomplete Spinal cord lesions.
There are different types of lesions that make up the incomplete spinal cord injury or lesion, they include the Anterior horn lesion, Central Cord Syndrome, Posterior Cord Syndrome, Anterior Cord Syndrome, and Brown Sequard Syndrome.,
Anterior Horn Lesion is a lesion that affects the Anterior grey horn. The anterior grey horn contains the lower motor neurons which innervate the skeletal muscles. Damage to the Anterior grey horn is damage to the lower motor neuron which would present with flaccid paralysis when it affects the bilateral region of the anterior grey horn. The Anterior Horn Lesion would lead to a decrease in the motor neuron, causing Hypotonia. The lesion could also lead to Fasciculations or Fibrillations, also Anterior horn lesions could also lead to decrease gamma motor neuron causing a decrease in deep tendon reflexes known as Hyporeflexia. Patients with Anterior Horn Lesions could have symmetric presentations or asymmetric presentations. Causes of this lesion include viruses such as poliomyelitis, West Nile virus, which attacks the anterior gray horn, Spinal muscular atrophy, a genetic condition, also affects the anterior gray horn, especially in infants. It could also be caused by sporadic diseases such as Amyotrophic lateral sclerosis which damages the upper motor neurons and the lower motor neuron causing lesions in both regions.,,,
Central Cord Syndrome is the most common incomplete spinal cord lesions. It is a lesson that encompasses the lateral corticospinal tracts (upper motor neurons lesion) [causing a bilateral upper motor neuron lesion which would lead to spastic paralysis, hypertonia, hyperreflexia, affecting more of the upper extremities to the lower extremities], the Anterior Gray Horn [causing lower motor neuron lesion, affecting the sympathetic neurons, which could lead to leads to Horner syndrome. Central Cord Syndrome affects the cervical and the thoracic region of the spinal cord], the Anterior White Commissure damaging the pain, pressure, and temperature pathway, causing bilateral loss of pain, pressure, crude touch, and temperature. One of the base causes of Central Cord Syndrome is Syringomyelia, but it could also be a result of minor trauma with patients who have underlying diseases such as cervical spondylosis, or accident, causing a hyperextension injury in the spinal cord. Another cause will be syringomyelia. ,,,
Posterior Cord Syndrome is one of the least common types of incomplete spinal cord lesion which occurs at the posterior aspect of the spinal cord, at the dorsal white column which carries proprioception, vibration, touch, sensations. When there is a lesion or an injury, it leads to a bilateral loss of touch (fine and discriminative), vibration, and proprioception. Treponema Pallidum which causes syphilis is one bacteria that is fond of destroying the dorsal white column of the spinal cord. Neuro Tabes dorsalis is another reason why the dorsal white column can be destroyed. Neuro syphilis can also cause Argyll Robertson pupil which is a result of destroying the dorsal white column. Also, it can be a result of a genetic cause, such as Friedreich's Ataxia which can damage the dorsal column, the corticospinal tract, and the spinal cerebellar tracts. Patients with multiple sclerosis can also suffer Posterior cord syndrome as a result of the demyelination of the axons of the dorsal column and it can cause Inter-nuclear optamoplegia, and vitamin B12 deficiency can lead to Posterior Cord Syndrome. ,,,,,.
Anterior Cord Syndrome is an incomplete spinal cord lesion that has to do with an injury or damage on two-thirds of the spinal cord. It occurs in the lower thoracic region, which causes damage to the descending autonomic fibers leading to fecal and urinary incontinence, symptoms associated with bilateral paralysis at the lesion level, and bilateral loss of pressure, pain, crude touch, and temperature. Thrombosis as a result of cardiovascular disease in the peripheral can cause anterior cord syndrome, Embolus can also lead to it, and Aortic trauma from dissection or repair could also cause Anterior cord syndrome. Cases of hyperflexion injury can also lead to the Anterior cord syndrome.,.
Brown Sequard Syndrome is also known as transverse hemisection of the spinal cord. It affects a transverse hemisection of the spinal cord and it can hit the posterior and the anterior part of the spinal cord. It affects the Posterior column causing a loss of tactile sensations, vibration sense, and proprioception, depending on the side which is affected. If the lesion affects the descending autonomic fibers in the cervical region, it could lead to horner syndrome. If it affects the corticospinal tract of the hemisection of the spinal cord, it could lead to ipsilateral upper motor neuron loss leading to Spastic paralysis, hypotonia, and hyporeflexia below the level where the lesion occurs. The Spinothalamic tract can also be damaged causing contralateral loss of pain, temperature, touch, and pressure sensations around 1 to 2 segments below the point of lesion. It would also damage a hemisection of the anterior grey horn causing ipsilateral motor neuron lesion-symptom which includes hypotonia, fasciculations, flaccid paralysis, and fibrillations at the lesion level. The causes of Brown Sequard Syndrome have to do with a deep cut into the spinal cord causing damage to the posterior column. Trauma from wounds such as gunshot wounds in the spinal cord can cause it. A spinal cord tumor can also lead to damage to the Posterior column.,,.
Complete Spinal Cord Lesions Just as the name sounds, it is a lesion on the entire spinal cord, affecting the motor functions, sensory functions, and autonomic functions below the lesion. This could cause Paraplegia (in the Thoracic region), Quadraplegia, (in the cervical region), complete Flaccid paralysis, hypotonia, and Araflexia, and this could become Spastic paralysis, hypertonia, and Hyperreflexia causing bilateral loss of sensation below the lesion region. ,
Image Reference
Image 1 || WIkimedia Commons || Kabir Spinal Cord Lesions and Syndromes