Wallenberg Syndrome

From EyeWiki


Disease

Wallenberg syndrome (WS) is a neurological disorder that is due to damage to the lateral portion of the medulla oblongata (i.e., the lateral medullary syndrome). WS is typically due to ischemia from a posterior inferior cerebellar artery infarction.[1] This monograph highlights the neuro-ophthalmic presentations for the WS.

Anatomy

The medulla can be divided into 4 regions: anteromedial, anterolateral, lateral, and posterior ( Figure 1). These regions are divided based on their differing arterial supply. The primary blood supply to the medulla comes from the vertebral arteries. The vertebral artery supplies the posterior inferior cerebellar artery (PICA), which has 3 main branches: the dorsal, medial, and lateral medullary branches. The dorsal medullary branch of PICA perfuses the posterior medulla. The medial medullary branch of PICA perfuses the anterior lateral medulla, and the lateral medullary branch perfuses the lateral medulla. The anterior spinal artery provides blood flow to the remainder of the medulla. The anterior spinal artery has its own median medullary branch, which perfuses the anteromedial region of the medulla.[2] The blood flow and the cross-sectional anatomy of the medulla are illustrated in figures 1 and 2.

Figure 1: Blood supply to the medulla
Figure 2: cross-sectional anatomy of medulla including all nuclei and tracts

Etiology

WS is most commonly due to an occlusion of the PICA, resulting in ischemia and infarction of the lateral medulla. While most commonly due to PICA occlusion, other arteries, such as the vertebral artery or branches of PICA, can be involved as well.[1][2] Primary etiologies include atherosclerosis, hypertension and other vasculopathic risk factors. Other rarer causes such as vertebral artery dissection especially in predisposed younger individuals with Ehlers Danlos syndrome, Marfan syndrome, fibromuscular dysplasia and hypoplastic vertebral artery have been noted in prior literature.[3][4]

Ocular Manifestations

  • Horner syndrome (miosis, ptosis, upside down ptosis, anhidrosis)– due to disruption of the oculosympathetic chain, which descends through the lateral medulla
  • Ptosis from Horner syndrome
  • Oscillopsia due to rotary nystagmus – due to disruption of communicating neurons between brainstem and inferior cerebellar peduncle; patient experiences oscillopsia, nausea, vomiting, vertigo, dizziness[5]
  • Binocular oblique diplopia – secondary to skew deviation from disruption of otolithic input at the level of the brainstem[6]

Systemic Manifestations[2] (Table 1[7])

  • Ipsilateral facial pain/numbness
  • Contralateral body pain/numbness
  • Gait ataxia
  • Dysphagia – difficulty swallowing
  • Dysarthria – slurred speech
  • Dysphonia – disorderly voice
  • Palatal myoclonus – twitching mouth
Table 1: Neurological manifestations due to lesions of structures of the medulla -- specific structures affected and their manifestations of Wallenberg syndrome are listed in bold
Anatomical Structure of Medulla Signs and Symptoms
Medial lemniscus Contralateral loss of vibration and proprioception of body
Pyramid Contralateral motor loss
Inferior olivary nucleus Loss of motor coordination and learning
Lateral vestibulospinal tract Minor loss of vestibulomotor coordination
Ventral trigeminothalamic tract Ipsilateral loss of pain and temperature of face
Lateral spinothalalmic tract Contralateral loss of pain and temperature of body
Spinal tract of CN V Ipsilateral loss of pain and temperature of face
Spinal nucleus of CN V Ipsilateral loss of pain and temperature of face
Nucleus ambiguus Difficulty swallowing, elevating palate, hoarseness, dysphagia
Inferior vestibular nucleus Nausea, vomiting, vertigo
Medial vestibular nucleus Nausea, vomiting, vertigo
Nucleus solitarius Difficulty with taste and processing visceral sensory info
Dorsal motor nucleus of CN X Difficulty swallowing, elevating palate, hoarseness, dysphagia
Hypoglossal nucleus Difficulty with movement of tongue
Medial longitudinal fasciculus Disconjugate horizontal gaze

Treatment

Treatment for WS depends on its etiology. Because it is almost always caused by a stroke, treatment is time dependent. Because this condition is caused by a stroke of the brainstem, the use of intravenous tissue-type plasminogen activator can be used if administered within 4-5 hours of symptom onset.[8] Long term ophthalmic care after WS are designed to improve visual symptoms. Optical therapy, using eye patches or prisms , has been used to alleviate unresolved diplopia.

References

  1. 1.0 1.1 Saleem F, M Das J. Lateral Medullary Syndrome. [Updated 2019 Dec 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-.
  2. 2.0 2.1 2.2 Ogawa K, Suzuki Y, Oishi M, Kamei S. Clinical study of 46 patients with lateral medullary infarction. J Stroke Cerebrovasc Dis. 2015 May;24(5):1065-74.
  3. Galende, A.V., Camacho, A., Gomez‐Escalonilla, C., Penas, M., Juntas, R., Ramos, A. and Esteban, J. (2004), Lateral Medullary Infarction Secondary to Vertebral Artery Dissection Presenting as a Trigeminal Autonomic Cephalalgia. Headache: The Journal of Head and Face Pain, 44: 70-74. doi:10.1111/j.1526-4610.2004.04012.x
  4. Giannopoulos S, Markoula S, Kosmidou M, Pelidou SH, Kyritsis AP. Lateral medullary ischaemic events in young adults with hypoplastic vertebral artery. J. Neurol. Neurosurg. Psychiatry. 2007 Sep;78(9):987-9.
  5. Morrow, M.J. and Sharpe, J.A. (1988), Torsional nystagmus in the lateral medullary syndrome. Ann Neurol., 24: 390-398. doi:10.1002/ana.410240307
  6. Brandt TH, Dieterich M. Different types of skew deviation. Journal of Neurology, Neurosurgery & Psychiatry 1991;54:549-550.
  7. Berkowitz AL. eds. Clinical Neurology and Neuroanatomy: A Localization-Based Approach New York, NY: McGraw-Hill; . http://neurology.mhmedical.com.srv-proxy2.library.tamu.edu/content.aspx?bookid=1984&sectionid=147771107.Accessed March 24, 2020.
  8. Salerno A, Cotter BV, Winters ME. The Use of Tissue Plasminogen Activator in the Treatment of Wallenberg Syndrome Caused by Vertebral Artery Dissection. J Emerg Med. 2017 May;52(5):738-740.