CLINICAL CORRELATIONS

Benedikt's Syndrome

Syndrome caused by a midbrain lesion affecting the red nucleus and CN III fascicle

Red nucleus and CN III fascicle

The specific structures in the midbrain affected in Benedikt's Syndrome

Midbrain

The general location of the lesion in Benedikt's Syndrome

Ipsilateral CN III palsy and contralateral tremor, ataxia, involuntary movements

The characteristic deficits seen in Benedikt's Syndrome

Occlusion of interpeduncular branches of the basilar and posterior cerebral arteries

A common vascular cause of Benedikt's Syndrome

Millard-Gubler/Foville Syndrome

Syndrome caused by a caudal pons lesion affecting the CN VI/VII fascicles and corticospinal tract

Caudal basis pontis, CN VI/VII fascicles, and corticospinal tract

The specific structures in the caudal pons affected in Millard-Gubler/Foville Syndrome

Pons

The general location of the lesion in Millard-Gubler/Foville Syndrome

Ipsilateral CN VII palsy, ipsilateral CN VI palsy, and contralateral hemiplegia

The characteristic deficits seen in Millard-Gubler/Foville Syndrome

Occlusion of circumferential branches of the basilar artery, tumor, or abscess

Common causes of Millard-Gubler/Foville Syndrome

Midportion of the Basis Pontis Syndrome

Syndrome caused by a lesion in the midportion of the pons affecting the CN V fascicles and corticospinal tract

Midportion of basis pontis, CN V fascicles, and corticospinal tract

The specific structures in the midportion of the pons affected in Midportion of the Basis Pontis Syndrome

Ipsilateral trigeminal motor and sensory deficits and contralateral hemiplegia

The characteristic deficits seen in Midportion of the Basis Pontis Syndrome

Occlusion of paramedian and short circumferential branches of the basilar artery

A common vascular cause of Midportion of the Basis Pontis Syndrome

Locked-In Syndrome

Syndrome caused by a lesion in the ventral pons resulting in complete paralysis but preserved consciousness, blinking, and vertical eye movements

Ventral pons

The specific location of the lesion in Locked-In Syndrome

Basilar artery occlusion

The cause of Locked-In Syndrome

Complete paralysis (quadriplegia) with preserved consciousness, blinking, and vertical eye movements

The key deficits seen in Locked-In Syndrome

Medial Medullary Syndrome (Dejerine Syndrome)

Syndrome caused by a lesion in the medial medulla affecting the corticospinal tract, medial lemniscus, and hypoglossal nucleus

Medial medulla

The location of the lesion in Medial Medullary Syndrome

Anterior spinal artery infarct

A common cause of Medial Medullary Syndrome

Contralateral hemiparesis, contralateral loss of proprioception/vibration, and ipsilateral tongue weakness

The characteristic deficits seen in Medial Medullary Syndrome

Lateral Medullary Syndrome (Wallenberg Syndrome)

Syndrome caused by a lesion in the lateral medulla affecting the spinal trigeminal tract, spinothalamic tract, nucleus ambiguus, vestibular nuclei, and sympathetic tract

Lateral medulla

The location of the lesion in Lateral Medullary Syndrome

PICA occlusion

A common cause of Lateral Medullary Syndrome

Ipsilateral facial pain/temperature loss, contralateral body pain/temperature loss, dysphagia, hoarseness, vertigo, and ipsilateral Horner's syndrome

The characteristic deficits seen in Lateral Medullary Syndrome

Weber's Syndrome

Syndrome caused by a lesion in the cerebral peduncle affecting the oculomotor nerve and corticospinal tract

Cerebral Peduncle (Midbrain)

The location of the lesion in Weber's Syndrome

Ipsilateral oculomotor nerve palsy and contralateral hemiparesis

The characteristic deficits seen in Weber's Syndrome

Occlusion of interpeduncular branches of the PCA and posterior choroidal artery, or rarely glioma

Causes of Weber's Syndrome

Ocular motility disorders and contralateral motor signs

General findings associated with lesions in the midbrain

CN VI/VII deficits and contralateral motor deficits

General findings associated with lesions in the pons

CN IX-XII involvement and contralateral sensory/motor deficits

General findings associated with lesions in the medulla

Crossed findings

The hallmark clinical principle in brainstem lesions, characterized by cranial nerve deficit on one side and motor/sensory deficits on the opposite side

Flaccid paralysis, reduced muscle tone, hyporeflexia/areflexia, muscle atrophy, and fasciculations

Clinical findings associated with Lower Motor Neuron lesions

Damage to anterior horn cells or motor nerve fibers

The location of the lesion in Lower Motor Neuron pathology

Poliomyelitis or peripheral nerve injury

Common causes of Lower Motor Neuron lesions

Spasticity, increased muscle tone, hyperreflexia, and pathological reflexes (like Babinski sign)

Clinical findings associated with Upper Motor Neuron lesions

Complete Spinal Cord Transection Syndrome

Syndrome resulting from damage affecting all ascending and descending pathways and autonomic pathways below the lesion level

All ascending and descending sensory/motor pathways and autonomic pathways below the affected level

The structures affected in Complete Spinal Cord Transection Syndrome

Bilateral loss of all sensory modalities below the lesion, bilateral spastic paralysis below the lesion (after spinal shock), areflexia (during initial spinal shock), and loss of bowel/bladder control

Clinical features of Complete Spinal Cord Transection Syndrome

Severe spinal trauma, extensive tumor infiltration, or transverse myelitis

Common causes of Complete Spinal Cord Transection Syndrome

Anterior Cord Syndrome

Syndrome resulting from damage to the anterior two-thirds of the spinal cord, sparing the dorsal columns

Anterior two-thirds of the spinal cord, including corticospinal and anterolateral (spinothalamic) tracts

The structures affected in Anterior Cord Syndrome

Bilateral motor paralysis below the lesion and bilateral loss of pain and temperature sensation below the lesion, with preservation of proprioception, vibration, and fine touch

Clinical features of Anterior Cord Syndrome

Infarction due to anterior spinal artery occlusion, severe flexion injury of the spinal cord, or herniated disc compressing the anterior cord

Common causes of Anterior Cord Syndrome

Posterior Cord Syndrome

Syndrome resulting from damage primarily to the dorsal columns of the spinal cord

Dorsal columns (fasciculus gracilis and cuneatus)

The structures affected in Posterior Cord Syndrome

Bilateral loss of proprioception and vibration sense below the lesion and sensory ataxia with positive Romberg sign, with preservation of motor strength and pain/temperature sensation

Clinical features of Posterior Cord Syndrome

Trauma, multiple sclerosis, Vitamin B12 deficiency (subacute combined degeneration), or Tabes dorsalis (neurosyphilis)

Common causes of Posterior Cord Syndrome

Posterolateral Cord Syndrome

Syndrome resulting from damage to the dorsal columns and lateral corticospinal tracts

Dorsal columns and lateral corticospinal tracts

The structures affected in Posterolateral Cord Syndrome

Bilateral loss of proprioception and vibration, bilateral spastic paresis (upper motor neuron signs), sensory ataxia, and positive Babinski sign

Clinical features of Posterolateral Cord Syndrome

Vitamin B12 deficiency, nitrous oxide toxicity, or copper deficiency

Common causes of Posterolateral Cord Syndrome

Syringomyelia

Syndrome characterized by cavitation and gliosis of the central spinal cord, commonly in the cervical region

Cavitation and gliosis of the central spinal cord

The definition of Syringomyelia

Cervical cord

The spinal cord region most commonly affected by Syringomyelia

"Cape-like" bilateral loss of pain and temperature sensation over the shoulders and upper limbs, preservation of light touch and proprioception, and possible progression to LMN signs in upper limbs if the anterior horn is involved

Clinical features of Syringomyelia

Congenital (Chiari malformation) or acquired (trauma, tumors)

Etiologies of Syringomyelia

Conus Medullaris Syndrome

Syndrome resulting from damage to the lower sacral cord segments and sacral autonomic nuclei

Conus medullaris (lower sacral cord segments S2-S4) and sacral autonomic nuclei

The structures affected in Conus Medullaris Syndrome

Early onset bladder and bowel dysfunction, saddle anesthesia, bilateral relatively symmetric lower extremity weakness, and mixed upper and lower motor neuron signs in the lower limbs

Clinical features of Conus Medullaris Syndrome

Trauma (fracture/dislocation at L1), tumors, or ischemia affecting conal segments

Common causes of Conus Medullaris Syndrome

Cauda Equina Syndrome

Syndrome resulting from damage to the lumbosacral nerve roots within the vertebral canal below the conus medullaris

Lumbosacral nerve roots within the vertebral canal below the conus medullaris

The structures affected in Cauda Equina Syndrome

Asymmetric flaccid paralysis of lower extremities, asymmetric sensory loss in a dermatomal distribution, saddle anesthesia, severe radicular pain, and late-onset bladder and bowel dysfunction

Clinical features of Cauda Equina Syndrome

Massive lumbar disc herniation, tumors compressing the cauda equina, or epidural abscess or hematoma

Common causes of Cauda Equina Syndrome

Amyotrophic Lateral Sclerosis (ALS)

A disease affecting anterior horn cells, corticospinal tracts, brainstem motor nuclei, and primary motor cortex, characterized by mixed UMN and LMN signs

Anterior horn cells, corticospinal tracts, brainstem motor nuclei (particularly CN V, VII, IX, X, XII), and primary motor cortex

Affected structures in Amyotrophic Lateral Sclerosis

Mixed UMN and LMN signs

The characteristic combination of findings in Amyotrophic Lateral Sclerosis

Sparing of sensory pathways and Onuf's nucleus

Structures typically spared in Amyotrophic Lateral Sclerosis

Dysarthria, dysphagia, and weakness of facial and tongue muscles

Bulbar symptoms seen in Amyotrophic Lateral Sclerosis

Weakness of the diaphragm and intercostal muscles leading to respiratory failure

Respiratory muscle involvement in Amyotrophic Lateral Sclerosis

Spinal Cord Tumors

Neoplasms affecting the spinal cord classified as intramedullary, extramedullary-intradural, or extradural

Intramedullary

Classification of spinal cord tumors located within the cord

Extramedullary-intradural

Classification of spinal cord tumors located within the dura but outside the cord

Extradural

Classification of spinal cord tumors located outside the dura

Ependymoma and astrocytoma

Common types of intramedullary spinal cord tumors

Meningioma and schwannoma

Common types of extramedullary spinal cord tumors

Gradual onset of localized pain, progressive motor weakness, and sensory changes

Clinical features of spinal cord tumors

Epileptic seizures

Manifestations of synchronized discharges of a group of neurons in the cerebral cortex

Developmental abnormalities, infection, trauma, tumors, metabolic derangements, or stroke

Factors that can trigger epileptic seizures

Loss of consciousness

A characteristic of generalized epileptic seizures

Manifestations reflecting the function of the specific cortical area from which the discharges originate

Characteristics of focal epileptic seizures

Central sulcus region

A cortical area where focal epileptic discharges can result in both motor and sensory manifestations

Aphasia or dysphasia

Disorders in language function involving disturbances in the ability to comprehend and/or program symbols for communication

Wernicke's Aphasia

A fluent, posterior, sensory, or receptive aphasia characterized by normal-excessive speech output, empty speech, paraphasias, jargon aphasia, and impaired comprehension

Wernicke's area (posterior part of the superior temporal gyrus in the dominant hemisphere)

The location of the lesion typically causing Wernicke's Aphasia

Broca's Aphasia

A nonfluent, anterior, motor, or expressive aphasia characterized by limited, effortful speech, poor articulation, short phrases, and relatively preserved comprehension

Broca's area (pars opercularis and pars triangularis of the inferior frontal gyrus in the dominant hemisphere)

The location of the lesion typically causing Broca's Aphasia

Conduction Aphasia

An aphasia characterized by impaired repetition

Arcuate fasciculus

The location of the lesion typically causing Conduction Aphasia

Global Aphasia

An aphasia characterized by severe deficits in production, comprehension, and repetition

Large lesions affecting Broca's area, Wernicke's area, and the arcuate fasciculus

The typical cause of Global Aphasia

Transcortical Motor Aphasia

A nonfluent aphasia with intact repetition

Supplemental motor area or its connections

The location of the lesion typically causing Transcortical Motor Aphasia

Transcortical Sensory Aphasia

A fluent aphasia with poor comprehension and intact repetition

Watershed area between the MCA, PCA, and ACA

The location of the lesion typically causing Transcortical Sensory Aphasia

Mixed Transcortical Aphasia

A nonfluent aphasia with poor comprehension and intact repetition

Lesions that separate Broca's area, Wernicke's area, and the arcuate fasciculus from the rest of the brain

The cause of Mixed Transcortical Aphasia