Central Vestibular Pathology Flashcards
Describe the complete differential diagnosis of central vestibular disorders
A. TOXIC/METABOLIC/MEDICATIONS
B. VASCULAR HEADACHE
1. Migraine with/without aura, basilar migraine
2. BPV/Recurrent vertigo of childhood
3. Tension or Cluster headaches
4. Vertebrobasilar insufficiency
C. BRAINSTEM
1. Lateral medullary infarction (Wallenberg syndrome, PICA)
2. Lateral pontomedullary syndrome (AICA)
3. Subclavian Steal Syndrome
4. Cerebellar infarction or hemorrhage
5. Orthostatic hypotension
6. Labyrinthine Apoplexy
7. Paroxysmal Torticollis
8. Infectious
9. Meningitis
10. Encephalitis
11. Epidural abscess
12. Congenital Syphillis
D. CRANIOVERTEBRAL JUNCTION DISORDERS
- Basilar impression (CRROOP)
- Assimilation of the Atlas – C1 fused to Skull, Odontoid compression, Klippel-Feil
- Atlantoaxial dislocation – Odontoid compression due to laxity of the transverse ligaments; can be Congenital (Down, Achondroplasia), or Acquired (R/A, RPA, Griesel)
- Chiari malformation
- Syringobulbia Neurologic
- Multiple sclerosis
- Huntington
- Parkinson
- Progressive Supranuclear Palsy
- Multiple Systems Atrophy
- Pseudotumor cerebri (BIH)
- Vestibular epilepsy
- Cerebellar ataxia syndromes
- Multisensory disturbances
- Waardenburg
- Cogan (Autoimmune)
E. NEOPLASTIC - PRIMARY OR SECONDARY
- Brainstem lesions
- Aqueduct/Ventricle compressing neoplasms
- Cerebellar neoplasms
What percentage of dizziness is caused by central causes?
- 10-20%
What medications can be used in the management of central vertigo?
- Anticholinergics: Reduce vestibular neuro-excitability
- Monoaminergics: Reduce vestibular neuroexcitability
- Antihistamine: Histamine increases neural excitability
- Antidopaminergic: Reduces excitatory effect from dopamine receptors
What are the main branches of the vertebrobasilar system?
Vertebrobasilar system feeds the cerebellum
- AICA: Anterior inferior cerebellar artery
- PICA: Posterior inferior cerebellar artery
- Superior cerebellar artery
Kevan Page 81
Regarding Vertebrobasilar insufficiency, discuss:
1. What is the etiology?
2. What is the clinical presentation?
2. How is it treated?
ETIOLOGY:
- Atherosclerosis of one or more of the subclavian arteries, vertebral arteries, or basilar arteries, leading to insufficiency of blood flow and subsequent vertigo
- The vertebrobasilar system feeds the cerebellum, inner ear, and brainstem
- Rarely, may be due to subclavian steal syndrome
CLINICAL PRESENTATION:
- Sudden onset nausea, vomiting, vertigo, lasting minutes (essentially like a brainstem TIA)
- Associated with other brainstem/cerebellar deficits: headaches, diplopia, ataxia, numbness, weakness, oropharyngeal dysfunction
- 4 D’s
1. Dizziness
2. Diplopia
3. Dysphagia
4. Drop attacks
TREATMENT:
1. Acute Management
- If stroke suspected: CT to rule out hemorrhagic event
- If presents within 3 hours of onset of symptoms, get a Neurology consultation and IV tPA (NINDS guidelines)
- Non-Acute management
- Control of risk factors: Diabetes, HTN, dyslipidemia, smoking (e.g. antiHTNs, Statins)
- Symptomatic 50-99% stenosis: ASA or Warfarin (Equally effective, but Warfarin high risk of intracranial events, and ASA therefore preferred. Warfarin should be used if prior embolic stroke that is cardiac in origin)
- Platelet aggregation inhibitors (ticlopidine) - Non-acute Procedure Interventions:
- Stenting has mixed restults
- Endarterectomy for extracranial vertebral disease (indications are evolving)
Regarding Subclavian Steal Syndrome, discuss:
1. What is it/what is the etiology?
2. What is the clinical presentation?
3. What is the management?
SUBCLAVIAN STEAL SYNDROME:
- Occlusion/stenosis of the subclavian/innominate artery just proximal to the takeoff of the vertebral artery
- Results in siphoning (drawing off) from the vertebrobasilar system, causing retrograde flow to supply the upper extremity during activity
CLINICAL PRESENTATION:
1. Similar symptoms to vertebrobasilar insufficiency with any arm movement/activity
- Vertigo
- Blurred vision
- Headache
- Arm pain
- Bruits
- Differential brachial BPs
TREATMENT:
1. Similar to vertebrobasilar insufficiency
Kevan Otology Page 82
Regarding Chiari Malformations, discuss:
1. What are they?
2. What are the general symptoms?
3. What are the four types of chiari malformation?
4. What are other conditions associated with chiari malformations?
CHIARI MALFORMATIONS:
- Group of developmental hindbrain and spinal cord abnormalities
- Characterized by herniation of the contents of the posterior cranial fossa through the foramen magnum into the upper cervical spine
GENERAL SYMPTOMS:
- Ataxia, nystagmus, vertigo
- Occipital headaches
- Upper extremity weakness, pain, sensory loss
- May also have hydrocephalus, other CNS malformations
TYPES:
1. CHIARI I: Herniation of cerebellar tonsils through the foramen magnum > 5mm caudally
- Most common type is Syringomyelia
- Only type that can be acquired
- Often does not cause symptoms until adolescence or adulthood (sometimes referred to as adult Chiari malformation)
- CHIARI II: Herniation of cerebellar tonsils and brainstem (Protrusion of cerebellar vermis, lower pons, and medulla)
- aka. Arnold-Chiari malformation or Pediatric Chiari malformation
- May also cause obstructive hydrocephalus in addition to symptoms of Type 1
- Almost always associated with spina bifida
- Frequently presents as a myelomeningocele - CHIARI III: Herniation of Hindbrain (cerebellum ± brainstem) through an encephalocele (high cervical meningocele)
- Associated encephalocele, severe neurologic defects - CHIARI IV: Severe cerebellar hypoplasia or aplasia, without herniation
- aka. Dandy-Walker syndrome
- Controversial diagnosis, often considered obsolete
Other types from other sources:
1. Chiari 0: Syringomelia without hindbrain herniation
2. Chiari V: Cerebellar agenesis and occipital lobe herniation through the foramen magnum
Conditions associated with Chiari malformations:
1. Spina bifida
2. Syringomyelia
3. Hydrocephalus
4. Tethered cord syndrome
Regarding Wallenberg Syndrome, discuss:
1. What is it, and what are other names for it?
2. What is the etiology?
3. What are the nuclei involved?
4. What are the clinical features?
5. What is the management?
WALLENBERG SYNDROME:
- aka. Lateral Medullary Syndrome
ETIOLOGY:
- Infarction of the ipsilateral vertebral artery; OR
- Infarction of the ipsilateral posterior inferior cerebellar artery (PICA)
- Results in an infarction of a wedge of the DORSOLATERAL MEDULLA
NUCLEI INVOLVED:
1. Vestibular Nucleus (Vertigo, N/V, nystagmus)
2. Nucleus Ambiguus - Motor IX/X (Dysphagia, dysarthria, decreased pharyngeal reflex)
3. Dorsal nucleus of X - Parasympathetic for X
4. Descending Sympathetic pathway (Ipsilateral Horner’s syndrome)
5. Spinal Trigeminal Nucleus (Ipsilateral decreased facial sensation)
6. Inferior cerebellar peduncle (Ipsilateral cerebellar ataxia, dysmetria)
7. Spinothalamic trunk (contralateral pain/temperature sensation loss)
8. Facial nucleus if extends rostral (high up) enough
Summary:
1. Ipsilateral CN V (spinal trigeminal), VIII-X (hearing spared)
2. Sympathetic chain
3. Spinothalamic tract (contra pain/temp)
4. Inferior Cerebellar Peduncle
5. ± Facial nucleus (if extends rostral enough)
CLINICAL FEATURES:
1. Hallmark is contralateral pain/temperature deficits involving the trunk and extremities, with ipsilateral cranial nerve deficits
2. Sympathetic chain - Ipsilateral Horner’s Syndrome (ptosis, miosis, anhydrosis)
3. Vestibular nucleus - Spontaneous nystagmus
4. Ipsilateral facial pain, diplopia
5. Ipsilateral paralysis of palate, pharynx, larynx - dysphagia, dysphonia
6. Inferior Cerebellum Peduncle: Ipsilateral dysmetria, dysrhythmia, dysdiadochokinesia
7. Hearing loss not observed because the lesion is caudal to the cochlear nucleus
8. ± Ipsilateral facial nucleus
TREATMENT:
1. If caught acutely, within 3-4.5 hours post-onset, thrombolytics can be considered by Neurology
2. Endovascular revascularization (evolving field)
3. Otherwise, mainstay is supportive and symptomatic (enteral feeding, speech therapy, rehabilitation)
Kevan Otology Page 82
Regarding Dejerine Syndrome, discuss:
1. What is it/alternative names?
2. What are the causes?
3. What are the nuclei involved, and their respective clinical features?
4. What is the management?
DEJERINE SYNDROME:
- Aka. Medial Medullary Syndrome
CAUSES:
- Infarction of the paramedian branches of the anterior spinal artery
- Results in infarction of the medial medulla, which includes the:
1. Hypoglossal nucleus
2. Medial Lemniscus
3. Pyramidal fibres
NUCLEI INVOLVED + CLINICAL PRESENTATION
1. Hypoglossal nucleus: Ipsilateral tongue weakness, ipsilateral tongue deviation, dysarthria
2. Pyramidal fibres: Contralateral upper extremity weakness (or hemiplegia) depending on degree of infarct
3. Medial lemniscus: Contralateral loss of 2-point discrimination, proprioception, and vibration sense
MANAGEMENT:
1. Similar to lateral medullary syndrome
Kevan Otology Pg 83
Regarding Lateral Pontine Syndrome, discuss:
1. What are alternative names for this?
2. What are the causes?
3. What are the nuclei involed and subsequent clinical features?
LATERAL PONTINE SYNDROME:
- Aka. Marie-Foix syndrome
- Aka. Marie-Foix-Alajouanine Syndrome
CAUSES:
- Infarction of the Anterior inferior cerebellar artery (AICA)
- Middle cerebellar peduncle is typically the core of the affected territory
- Because the labyrinthine artery arises from the AICA in 80% of patients, comnbined cochleovestibular loss occurs in 60% of patients
NUCLEI INVOLVED / CLINICAL FEATURES:
1. Vestibular nucleus: Vertigo, N/V
2. Cochlear nucleus: Tinnitus, ipsilateral hearing loss
3. Spinal Trigeminal Nucleus: Ipsilateral decrease or changed facial sensation
4. Facial nucleus/CNVII: Ipsilateral facial weakness
5. Middle/Inferior Cerebellar Pedumcle: Ipsilateral cerebellar ataxia or dysmetria
6. Spinothalamic tract: Contralateral pain/temperature deficits
- Overall, onset of symptoms are acute and followed by gradual improvement
What are the features that differentiate Lateral Medullary Syndrome and Lateral Pontine Syndrome?
- LMS presents with dysarthria and dysphagia, while LPS does not (does not involve IX/X)
- LPS can present with hearing loss and/or facial weakness, while LMS does not
MNEMONICS:
1. Lateral medullary syndrome affects nucleus ambiguous and causes dysarthria and dysphagia
- PICA infarction results in ability to ‘chew’ –> PICA-CHEW (Pikachu)
- Lateral Pontine syndrome may affect facial motor nucleus/facial nerve and cause facial weakness
- AICA infarction results in fACIAl weakness (AICA backwards)
Regarding Basilar Impression/Invagination, discuss:
1. What is it?
2. Define the following: Chamberlain’s line, Wackenheim’s Clivus-Canal line, McRae Line, McGregor Line, Height Index of Klaus, Spinous Interlaminar Line (posterior canal line)
4. What are the signs/symptoms of basilar impression/invagination?
5. What are 6 etiologies of basilar impression?
BASILAR IMPRESSION/INVAGINATION:
- Congenital or acquired craniocervical junction abnormality, where the tip of the odontois process projects above the foramen magnum
- Aka. Atlantoaxial impaction or vertical cranial settling
- Extension of the odontoid process above Chamberlain’s line >3mm, or posterior to Wackenheim’s line, or < 30mm from the Height index of klaus indicates impression likely exists
TERMINOLOGY:
- Chamberlain’s Line (Palato-canal): Line between hard palate and posterior edge of foramen magnum (Opisthion)
- Wackenheim’s Clivus-Canal line: Extension of clival line through foramen magnum
- McGregor Line: From posterior margin of the hard palate to the Lowest point of the occipital squamosal surface
- McRae line: From basion to opisthion
- Height Index of Klaus: Line drawn from the tuberculum sellae to the internal occipital protuberance. The vertical distance between this line and the apex of the odontois is the height index of klaus
- Interlaminar spinous line/Spinolamellar line: Line drawn from interoccipital ridge above and down along the fused spinous process of C2/3, and also intersect posterior arch of atlas (C1; the axis is C2). If atleas if sued, posterior arch is anterior to the line, and therefore posterior compression of spinal cord occurs
SIGNS/SYMPTOMS:
1. Headache (usually pain in back of head or upper neck)
2. Neck weakness
3. Nystagmus
4. Trouble talking or swallowing
5. Dizziness
6. Numbness/tingling in hands/feet
7. Loss of proprioception
8. Shock sensation down back with neck flexion (L’Hermitte’s)
9. Weakness/extremity paralysis
10. Urinary or fecal incontinence
ETIOLOGIES:
1. Cretinism (hypothyroidism)
2. Rheumatoid arthritis
3. Rickets (the softening and weakening of bones in children, usually because of an extreme and prolonged vitamin D deficiency)
4. Osteomalacia
5. Osteogenesis Imperfecta (Van Der Hoeve Syndrome)
6. Paget’s disease
CRROOP
Basilar Invagination: https://www.childrenshospital.org/sites/default/files/media_migration/c2917e49-4c46-4b10-be27-f3b943c61cb1.png
Vancouver 259
Chamberlain: https://prod-images-static.radiopaedia.org/images/23621379/e620bcb852a4b1ad176210994ccbb8_gallery.jpeg
McGregor: https://www.researchgate.net/profile/Mehmet-Bilgin-Eser/publication/330970865/figure/fig2/AS:724140680019971@1549660000957/Scheme-Demonstrates-differences-between-Chamberlain-line-from-McGregor-line.ppm
Klaus: https://ars.els-cdn.com/content/image/3-s2.0-B9780750613613500082-f02-08-9780750613613.gif
Spinolamellar: https://radiologykey.com/wp-content/uploads/2016/07/C11-FF4-4.gif
Regarding Cerebellar ataxia syndromes, discuss:
1. What is Ataxia?
2. What is the nystagmus typically associated with these syndromes?
3. List 8 different types of Cerebellar ataxia
ATAXIA:
- Loss of coordination of muscle movements
NYSTAGMUS PATTERNS:
- Abnormal nystagmus including gaze-paretic nystagmus and rebound nystagmus is common
TYPES OF CEREBELLAR ATAXIA SYNDROMES:
1. Paraneoplastic cerebellar degeneration
2. Familial Episodic Ataxia
3. Ataxia Telangiectasia
4. Spinocerebellar atrophy
5. Cerebellar atrophy (Dandy-Walker/Chiari 4)
6. Alcoholic Cerebellar degeneration
7. Refsum’s Disease
8. Friedreich’s ataxis
Regarding Paraneoplastic Cerebellar degeneration, discuss:
1. What is it caused by?
2. What are the most common associations?
PARANEOPLASTIC CEREBELLAR DEGENERATION:
- Due to anti-Purkinje cell antibodies in patients with undiagnostic and otherwise asymptomatic malignancies
- Purkinje cells = neurons specific to the cerebellar cortex
ASSOCIATIONS:
1. Small cell carcinoma of the lung
2. Breast cancer
3. Ovarian cancer
4. Cancer of the female genital tract
5. Autoimmune mechanism
Regarding Familial Episodic Ataxia, discuss:
1. What is the genetics/inheritance?
2. What are the clinical presentations?
2. What causes it? What are the triggers?
3. What are the treatments?
INHERITANCE:
- Autosomal dominant
- 8 different types, most frequent are EA1 and EA2, caused by mutations in KCNA1 and CACNA1A
CLINICAL PRESENTATION:
- Recurrent attacks of cerebellar dysfunction/ataxia and vertigo
CAUSE:
- Abnormal intracellular pH
TRIGGERS:
1. Stress
2. Exercise
TREATMENT:
1. EA1: Carbonic anhydrase inhibitors, phenytoin
2. EA2: Acetazolamide
