Plantar reflex

In medicine and neurology, the Babinski reflex or Babinski sign is a reflex that can identify disease of the spinal cord and brain and also exists as a primitive reflex in infants. When non-pathological it is called the plantar reflex while the term Babinski's sign refers to its pathological form.

Babinksi's reflex occurs when the great toe extends with abduction of the other toes in response to a stimulus on the outside of the sole.
 * Positive response:
 * Great toe dorsiflexion
 * Abduction of other toes
 * A positive Babinski's reflex is representative of a normal spinal reflex
 * Normal in young children (2 years old and younger)
 * Due to immaturity of pathways

Methods
The lateral side of the sole of the foot is rubbed with a blunt implement so as not to cause pain, discomfort or injury to the skin; the instrument is run from the heel along a curve to the metatarsal pads. There are three responses possible:
 * Flexor: the toes curve inward and the foot everts; this is the response seen in healthy adults.
 * Indifferent: there is no response.
 * Extensor: the hallux extends upward, and the other toes fan out - the Babinski's sign indicating damage to the central nervous system.

As the lesion responsible for the sign expands so does the area from which the afferent Babinski response may be elicited. The Babinski response is also normal while asleep and after long period of walking.

Interpretation
The Babinski’s sign can indicate upper motor neuron damage to the spinal cord in the thoracic or lumbar region, or brain disease constituting damage to the corticospinal tract. Occasionally, a pathological plantar reflex is the first (and only) indication of a serious disease process, and a clearly abnormal plantar reflex often prompts detailed neurological investigations, including CT scanning of the brain or MRI of the spine, as well as lumbar puncture for the study of cerebrospinal fluid.

In infants
Infants will also show an extensor response. A baby's smaller toes will fan out, and their big toe will dorsiflex slowly. This happens because the corticospinal pathways that run from the brain down the spinal cord are not fully myelinated at this age, so the reflex is not inhibited by the cerebral cortex. The extensor response disappears and gives way to the flexor response around 12-18 months of age.

Complete Differential Diagnosis of a Positive Babinski Reflex
In alphabetical order.


 * Alzheimer's Disease
 * Amyotrophic Lateral Sclerosis (ALS)
 * Arteriovenous malformation
 * Brain abscess
 * Brain tumor
 * Brown-Sequard Syndrome
 * Cavernous malformation
 * Cerebral Palsy
 * Cerebritis
 * Ceroid lipofuscinosis
 * Embolism
 * False positive
 * Familial periodic paralysis
 * Freidrichs Ataxia
 * Funicular myelosis
 * Gangliosidoses
 * Head injury
 * Hepatic encephalopathy
 * Hypoglycemia
 * Meningitis
 * Multiple Sclerosis
 * Parkinson's Disease
 * Pernicious anemia
 * Poliomyelitis
 * Post cardiac-arrest state
 * Postictal state
 * Rabies
 * Sedative-hypnotic drug intoxication
 * Severe metabolic disturbance
 * Sialidoses
 * Spinal cord hemorrhage
 * Spinal cord infarction
 * Spinal cord injury
 * Spinal cord tumor
 * Stroke
 * Subarachnoid hemorrhage
 * Syringomyelia
 * Tabes dorsalis
 * Tetanus
 * Tonic-clonic seizure (generalized)
 * Tuberculosis
 * Venous sinus thrombosis
 * Viral encephalitis
 * Wallenberg's Syndrome

Relationship to Hoffmann sign
The Hoffmann's sign is occasionally said to be the upper limb equivalent of the Babinski's sign because both indicate upper motor neuron dysfunction. Mechanistically, they differ significantly; the finger flexor reflex is a simple monosynaptic spinal reflex involving the flexor digitorum profundus that is normally fully inhibited by upper motor neurons. The pathway producing the plantar response is more complicated, and is not monosynaptic. This difference has led some neurologists to reject strongly any analogies between the finger flexor reflex and the plantar response.

Other Imaging Findings

 * Spinal cord and brain imaging have greatest sensitivity and specificity for determining pathology of a positive Babinski's reflex
 * Magnetic resonance angiogram (MRA) (stroke patients)
 * Carotid doppler (stroke patients)
 * Electroencephalogram (EEG) (seizure activity)

Other Diagnostic Studies

 * Cerebrospinal fluid cultures
 * Lumbar puncture
 * Reflex testing of arms and finger flexor response (increased reflexes indicate location of lesion in the brain or cervical cord)

Treatment

 * Reduction of risk factors (cerebral infarction
 * Physical therapy (spinal cord infarction)
 * Observation (postictal state)

Acute Pharmacotherapies

 * Antiplatelet therapy (cerebral infarction)
 * Warfarin therapy (cerebral infarction)
 * Antibiotics (encephalitis, brain abscess, meningitis, cerebritis)
 * Anticonvulsant drugs (postictal state)
 * Antivirals (encephalitis, meningitis, cerebritis)

Surgery and Device Based Therapy

 * Surgery to relieve epidural or subdural hematoma
 * Surgical decompression (spinal cord hemorrhage)
 * Drainage of brain abscess
 * Radiosurgery (cavernous malformations, arteriovenous malformation)
 * Surgical clipping (cerebral aneurysm)
 * Intra-arterial embolization (cavernous malformations, arteriovenous malformation)
 * Carotid surgery (cerebral infarction)

Eponym
The pathological reflex is named after Joseph Jules François Félix Babinski (1857-1932), a French neurologist of Polish descent.