MED-NERD
Locked-In Syndrome (LIS)
Outline:
- Overview
- History of Locked In Syndrome
- Incidence
- Classification
- Clinical picture
- Complications
- Diagnosis
- Management
- Prognosis
- Conclusion
- References
Overview:
Locked-in syndrome (LIS) is caused by any lesion affecting the ventral pons or the caudal ventral midbrain. Ischemic causes are common such as occlusion of the basilar artery. Trauma and haemorrhage can also cause LIS. The symptoms in case of strokes, trauma, or metabolic demyelination are acute.
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Magnetic resonance image (MRI) showing infarction in lower pons that caused Locked-in syndrome. Source: SpringerLink |
History of LIS:
LIS was first defined in 1966 as quadriplegia (loss of movement in the four extremities), lower cranial nerve paralysis, and mutism with preservation of consciousness, vertical gaze, and upper eyelid movement. It was redefined in 1986 as quadriplegia and anarthria with preservation of consciousness.
Incidence:
- It is a rare neurological disorder.
- It is difficult to determine the actual number of LIS cases as many cases may be misdiagnosed or unrecognized.
- Sex: Males and females may be equally affected, but the ALIS study has shown 51.2% of men diagnosed vs. 48.1% of women diagnosed.
- Age: adults are commonly affected due to the high risk of brain stroke and bleeding. The mean age ranges from 30-50 years, but children can also be affected.
Classification:
According to Bauer et al. Classification, LIS is classified into 3 types :
classical, partial, and complete LIS.
- Classical LIS: Quadriplegia and anarthria.
- Partial LIS: Some motor functions are preserved.
- Complete LIS: Quadriplegia, loss of blinking and vertical gaze, and inability to communicate.
Clinical picture:
The clinical picture may vary according to the cause which makes the initial diagnosis difficult. The Initial presentation may include :
- Quadriplegia: Due to involvement of the corticospinal tracts.
- Bulbar palsy: anarchic and dysphagia.
*Anarthria: due to paralysis of the facial-gloss-pharyngeal-laryngeal muscles and damage of the corticobulbar fibres.
- Sensory loss
- Usually vertical eye movement is preserved: due to the location of the nucleus in the rostral portion of the midbrain.
- Retention of hearing.
- Blinking and consciousness are preserved: functional MRI usually shows normal activity.
- Loss of Medial and lateral gaze.
- Diplopia and blurry vision.
- Impairment of Respiration including apnea, ataxia, and hyperpnea:due to involvement of lateral tegmentum.
- Impairment of attention, executive function, perception, intellectual ability, and visual and verbal memory.
- Dizziness, Vertigo
- patients are usually conscious.
Complications of LIS:
- Immobilization leading to: joint contracture, muscle atrophy, and pulmonary embolus.
- Cardiopulmonary disorders.
- Urinary tract infection.
- Pulmonary complications are considered the leading cause of death. In case of high spinal cord injury, pulmonary complications are accompanied by reduced vital capacity, aspiration of saliva, due to dysphagia and impaired cough reflex lead to other complications, including atelectasis pneumonia.
Diagnosis:
The diagnosis of LIS is often triggered by a member of the care staff or a family member in unresponsive patients.
- Magnetic resonance imaging (MRI): showing damage to the pons and this is the most valuable test.
- Magnetic resonance angiography: showing the blood clot in the brainstem arteries.
- Electroencephalogram (EEG): measuring electrical activity of the brain, and may be showing normal brain activity and sleep-wake cycles.
- Electromyography and nerve conduction: to rule out damage to the muscles and nerves.
- Cerebrospinal fluid examination (CSF): may reveal an infectious or autoimmune cause of LIS.
- Blood tests:
*hypophosphatemia, Hyponatremia, and hypomagnesemia: may cause comas similar to a LIS.
*Glucose evaluation: to rule out a hypoglycaemic coma.
*A complete blood count( CBC ): to rule out coma caused by sepsis.
Management :
The initial management is maintaining an airway and adequate oxygenation through a tracheostomy. Managing reversible medical causes and reducing risk factors are essential while preventing the complications of immobility, dysphagia, and incontinence.
- Chest physiotherapy, including deep breathing exercises, frequent positional changes, postural drainage, and suctioning, may limit pulmonary complications.
- Corneal ulceration, due to impaired eye closure, can be treated by lateral tarsorrhaphy or botulinum therapy.
- Treatment of the underlying cause ( such as intraarterial thrombolytic therapy for reversal of a basilar artery thrombosis) may be useful up to six hours after symptoms onset.
- Intravenous steroids or radiation for treatment of tumours.
- Feeding and drinking through a gastrostomy.
- It is important to establish eye-coded communication. An agreed system of interpretation is necessary, where one upward movement signifies yes and two rapid upward movements, no. Assisted technology such as infrared eye movement sensors or computer modulated voice prosthetics may be used for speech therapy to improve communication gradually.
- Meningitis and abscesses may be treated with broad-spectrum antibiotics.
Prognosis :
Mortality and recovery vary depending on the cause of LIS.
- LIS shows a high mortality rate in the acute cases. Studies have shown a 5-year mortality rate of 84% and a 10-year and 31%,
- All patients with the locked-in syndrome should be rehabilitated in a national or regional specialist centre that has specific multidisciplinary rehabilitation experience with the condition.
- Many patients choose to return to live at home, which presumably enables greater social interaction with family and friends. Return to home life may positively influence the patient's desire to live. However, it places a long term physical and psychological burden on the family.
See :
This is one of the miracles ! Richard Marsh who had a stroke in 2009 , is one of the survivors from locked-in syndrome and is telling his story .
Conclusion:
Locked-in syndrome is a rare disorder usually has a poor prognosis. It is often difficult to diagnose it since the condition shares many features with other diseases. Some patients continue their lives through eye communication. Locked-in syndrome represents a challenge for both patients and healthcare providers.
References :
(1) Halan T, Ortiz JF, Reddy D, Altamimi A, Ajibowo AO, Fabara SP. Locked-In Syndrome: A Systematic Review of Long-Term Management and Prognosis. Cureus. 2021 Jul 29;13(7):e16727. doi: 10.7759/cureus.16727. PMID: 34471579; PMCID: PMC8402869.
(2) Law YM, Feng LF, Liang Q, Meng LJ, Shen P, Yu SJ, Pao WY. Effect of Exercise on Physical Recovery of People with Locked-In Syndrome after Stroke: What Do We Know from the Current Evidence? A Systematic Review. Cerebrovasc Dis Extra. 2018;8(2):90-95. doi: 10.1159/000490312. Epub 2018 Jul 13. PMID: 30007974; PMCID: PMC6489030.
(3) Smith E, Delargy M. Locked-in syndrome. BMJ. 2005 Feb 19;330(7488):406-9. doi: 10.1136/bmj.330.7488.406. PMID: 15718541; PMCID: PMC549115.
(4) Lulé D, Zickler C, Häcker S, Bruno MA, Demertzi A, Pellas F, Laureys S, Kübler A. Life can be worth living in locked-in syndrome. Prog Brain Res. 2009;177:339-51. doi: 10.1016/S0079-6123(09)17723-3. PMID: 19818912.
(5) Bruno MA, Pellas F, Bernheim JL, Ledoux D, Goldman S, Demertzi A, Majerus S, Vanhaudenhuyse A, Blandin V, Boly M, Boveroux P, Moonen G, Laureys S, Schnakers C. Quelle vie après le Locked-In syndrome? [Life with Locked-In syndrome]. Rev Med Liege. 2008 May-Jun;63(5-6):445-51. French. PMID: 18669218.
(6) NORD , assistance in the preparation of this report: Francesca Pistoia, MD, PhD, Neurologist and Assistant Professor of Neurorehabilitation, University of L'Aquila, Italy, and Steven Laureys, MD, PhD, Coma Science Group, University Hospital of Liege, Belgium.
(7) M Das J, Anosike K, Asuncion RMD. Locked-in Syndrome. [Updated 2021 Aug 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-.
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