manifestations neurologiques
Posté : 30 mars 2006 12:01
Nervous System Manifestations of Lyme Disease in Children
(traduction voir plus bas)
By Michael K. Sowell, MD (Pediatric Neurologist) November, 1999
Lyme disease is the most common vector-borne (transmitted by non-humans) disease in the United States and Europe. It is a multi-system disease which may affect the skin, eyes, heart, musculoskeletal system and nervous system.
Lyme disease in children merits special consideration because of its potentially devastating effects on the developing brain. Furthermore, some of the neurologic symptoms of Lyme disease may be more difficult to elucidate in children because of their inability to convey their symptoms, due to their developmental limitations.
It is said that Lyme disease is the “New Great Imitator", which emphasizes that Lyme disease can affect virtually any area of the nervous system as well as imitate other diseases. This is particularly true in view of the difficulties of establishing a firm diagnosis (reviewed elsewhere). This brief article is intended to be an overview of the potential neurologic manifestations of Lyme disease in children.
One of the most difficult challenges of writing this article is to translate medical terminology into plain English that is understandable to the average non-medically trained person. I am accepting that challenge, but please understand there may be concepts that are either difficult to understand or are grossly oversimplified.
Knowledge of the anatomy of the nervous system and localization of the disease process through a combination of history, physical examination and testing (such as MRI, blood tests, etc.) is of the utmost importance in making the correct neurologic diagnosis.
The nervous system is classically divided into five different areas:
brain
spinal cord
peripheral nerve
nerve-muscle junction
muscle
Again, simplistically speaking, the brain is divided into two hemispheres (right and left), the cerebellum and the brain stem. The cerebral hemispheres are responsible for our so-called higher cortical functions, such as speech, mentation, vision, language processing and the initiation of movement and interpretation of sensations. The extrapyramidal system is deep between the two hemispheres and controls precision of movements. Disorders of the extrapyramidal system cause tics, muscle jerks and some twitches and tremors. The cerebellum is largely responsible for the coordination of movements. The brainstem controls basic, primitive functions (such as smell, eye movements, vision, facial sensation and movement, hearing, balance, tongue movements and swallowing).
The spinal cord is encased within the bony spinal column and carries nerve signals involving sensation and motor functions between the brain and the remainder of the nervous system. The brain and spinal cord together are collectively called the central nervous system.
The peripheral nerve is where both sensory and motor signals are carried to and from the spinal cord. A nerve root (radicle) is where the peripheral nerve joins the spinal cord. We thus hear terms like radiculopathy, polyradiculopathy, and polyradiculoneuropathy. These terms loosely refer to irritation of one or, more commonly, multiple nerve roots. The nerve-muscle junction (neuromuscular junction) is where the peripheral nerve communicates with the muscle.
When people refer to skeletal muscle, they are usually referring to skeletal muscle which is involved in our bodies' movement. However, keep in mind that Lyme disease may also involve the heart muscle and smooth muscle (muscle of the gastrointestinal tract).
The peripheral nerve, nerve-muscle junction, and muscle are collectively referred to as the peripheral nervous system.
With this brief overview, we will now look at some ways that Lyme disease may involve the nervous system. Each condition will be categorized according to the area of the nervous system predominantly affected (which, in itself, is a gross oversimplification, since usually more than one area is affected at a time.)
Brain:
Neuroborreliosis may affect the brain in a number of ways, including:
Aseptic meningitis:
Usually manifested by headache, neck stiffness, fever and disorientation or confusion. It is often mild and may not be sufficient to result in the patient seeking medical attention This may last for hours, days or months, but typically occurs in the initial stages.
Seizures:
Often characterized by abrupt transient loss of consciousness, twitching and jerking. Respiratory distress may occur in a percentage of patients. EEGs may be done to assist in the diagnosis, but findings are not specific to Lyme disease.
Encephalopathy:
Characterized by more chronic cognitive changes, which may involve impaired speech (both receptive and expressive), disorientation, impaired memory, irritability and decreased level of awareness to one's environment. There may be a number of other neuropsychiatric changes, detailed well by Drs. Fallon, et al. Patients with chronic Lyme disease may initially be misdiagnosed with a primary psychiatric disorder. Children with neuroborreliosis may present with developmental delay or, later, with school failure or symptoms of attention deficit disorder, thus being mislabeled as having attention deficit hyperactivity disorder. Whereas ADHD as a primary diagnosis is much more common, neuroborreliosis needs to be included as a possibility, particularly in the child who is exhibiting other possible symptoms of Lyme disease.
Increased intracranial pressure:
Reported in several children with Lyme disease, this would typically present with headaches, double vision and, occasionally, vomiting. In my view, this has been erroneously reported as a "pseudotumor cerebri-like" syndrome. True pseudotumor cerebri is defined by elevated intracranial pressure after the exclusion of all potential causes, including chronic infection. Thus, I think that this title is not accurate and may be misleading.
Extrapyramidal system:
This may be involved in Lyme disease, with symptoms ranging from muscle jerks, rigidity, tremors, exaggerated sleep jerks (myoclonus), tics and cramps.
Cerebellum:
Possibly involved in Lyme disease as manifested by ataxia, a medical term meaning poorly coordinated gait, often accompanied by frequent falling. Ataxia is a symptom, not a diagnosis, and can occur from impairment in different areas of the nervous system
Brainstem:
It can be affected by Lyme disease due to cranial nerve palsies. Cranial nerve involvement has been reported in virtually all of the cranial nerves. Vertigo and dizziness/dysequilibrium from both CNS and PNS dysfunction have been reported with Lyme disease.
Spinal cord:
Transverse myelitis:
An acute disorder of the spinal cord involving area(s) of inflammation or infection that causes motor or sensory malfunction, possibly leading to permanent impairments. As such, it may be due to a variety of possible causes, including multiple sclerosis, viruses or Lyme disease, all of which merit careful investigation.
Peripheral Nerve:
Peripheral neuropathies:
These have been reported, although they are said to be less common in children. They may be sensory (involving abnormal or diminished sensation), which may involve pain, tightness, numbness and tingling or other unusual sensations. Motor neuropathies typically involve weakness and reduced muscle strength and/or bulk in the affected area. Often peripheral neuropathies are mixed motor and sensory.
Radiculoneuropathies:
Involve irritation at the level of the nerve root, where the peripheral nerve joins the spinal cord. Typically, there is pain or discomfort near the spine. Both radiculoneuropathies and peripheral neuropathies may be further defined by eloctromyography and nerve conduction studies (EMG/NCVs), the findings of which are not specific to, or diagnostic of, Lyme disease.
Neuromuscular Junction:
Myasthenia Gravis-like syndrome:
Rarely reported in children, it involves a decrement in muscle power with sustained muscle contraction. This must be confirmed by EMG/NCV.
Muscle:
Myositis:
This is common among patients with both early and late chronic Lyme disease. Muscle symptoms include muscle tenderness, stiffness, cramping and muscle swelling.
In summary, Lyme disease may affect virtually any area of the nervous system and lead to a variety of manifestations, either in isolation or in combination. In addition, as more appropriately reviewed elsewhere, Lyme disease is foremost a clinical diagnosis, with marked difficulties in establishing confirmatory laboratory tests. In addition, concomitant infections may exist, which often need to be addressed. Furthermore, there exists ongoing controversy regarding the duration and nature of therapy, although it can be stated unequivocally that therapy must be individualized.
Lyme disease in children may affect the nervous system in virtually every way that it can in adults, plus it has the added potential for detrimental effects on the developing brain in particular. Pediatricians and pediatric subspecialists face the added challenge of the developmental limitations involved in conveying symptoms from patient to physician.
It should always be borne in mind that Lyme disease is treatable and merits aggressive therapy in order to avoid potentially permanent devastating neurologic impairment.
Suggested Reading:
Belman AL, Coyle PK, Roque C, et al: MRI Findings in Children Infected by Borrelia burgdorferi. Pediatric Neurology 8:428-31.
Belman AL, Iyer M, Coyle PK, et al: Neurologic Manifestations in children with North America Lyme Disease. Neurology 43:2609-2614.
Demaerel P, Wilms G., Casteels K, et al: Childhood neuroborreliosis: clinicoradiological correlation. Paediatric Neuroradiology 37:578-581.
Fallon BA, Nields JA: Lyme Disease: A Neuropsychiatric Illness. Am J Psychiatry 151:1571-1583.
Lawrence C, Lipton RB, Lowry FD and Coyle PK: Seronegative Chronic Relapsing Neuroborreliosis. European Neurology 35: 113-117.
Lesser RL, Kornmehl EW, Pachner AR, et al: Neuro-Opthalmologic Manifestations of Lyme Disease. Ophthalmology 97:699-706.
Pachner AR and Steere AC: The triad of neurologic manifestations of Lyme disease: Meningitis, cranial neuritis, and radiculoneuritis. Neurology 35: 47-53.
Pachner AR: Borrellia burgdorferi in the Nervous System: The New "Great Imitator”. Annals of the New York Academy of Sciences 539: 56-64.
Reik L, Jr.: Lyme Disease. In Scheld WM, Whitley, Durack DT, eds: Infections of the Nervous System, New York, 1996, Raven Press.
Zaidman GW: The Ocular Manifestations of Lyme Disease. International Ophthalmology Clinics 33: 9-22
(traduction voir plus bas)
By Michael K. Sowell, MD (Pediatric Neurologist) November, 1999
Lyme disease is the most common vector-borne (transmitted by non-humans) disease in the United States and Europe. It is a multi-system disease which may affect the skin, eyes, heart, musculoskeletal system and nervous system.
Lyme disease in children merits special consideration because of its potentially devastating effects on the developing brain. Furthermore, some of the neurologic symptoms of Lyme disease may be more difficult to elucidate in children because of their inability to convey their symptoms, due to their developmental limitations.
It is said that Lyme disease is the “New Great Imitator", which emphasizes that Lyme disease can affect virtually any area of the nervous system as well as imitate other diseases. This is particularly true in view of the difficulties of establishing a firm diagnosis (reviewed elsewhere). This brief article is intended to be an overview of the potential neurologic manifestations of Lyme disease in children.
One of the most difficult challenges of writing this article is to translate medical terminology into plain English that is understandable to the average non-medically trained person. I am accepting that challenge, but please understand there may be concepts that are either difficult to understand or are grossly oversimplified.
Knowledge of the anatomy of the nervous system and localization of the disease process through a combination of history, physical examination and testing (such as MRI, blood tests, etc.) is of the utmost importance in making the correct neurologic diagnosis.
The nervous system is classically divided into five different areas:
brain
spinal cord
peripheral nerve
nerve-muscle junction
muscle
Again, simplistically speaking, the brain is divided into two hemispheres (right and left), the cerebellum and the brain stem. The cerebral hemispheres are responsible for our so-called higher cortical functions, such as speech, mentation, vision, language processing and the initiation of movement and interpretation of sensations. The extrapyramidal system is deep between the two hemispheres and controls precision of movements. Disorders of the extrapyramidal system cause tics, muscle jerks and some twitches and tremors. The cerebellum is largely responsible for the coordination of movements. The brainstem controls basic, primitive functions (such as smell, eye movements, vision, facial sensation and movement, hearing, balance, tongue movements and swallowing).
The spinal cord is encased within the bony spinal column and carries nerve signals involving sensation and motor functions between the brain and the remainder of the nervous system. The brain and spinal cord together are collectively called the central nervous system.
The peripheral nerve is where both sensory and motor signals are carried to and from the spinal cord. A nerve root (radicle) is where the peripheral nerve joins the spinal cord. We thus hear terms like radiculopathy, polyradiculopathy, and polyradiculoneuropathy. These terms loosely refer to irritation of one or, more commonly, multiple nerve roots. The nerve-muscle junction (neuromuscular junction) is where the peripheral nerve communicates with the muscle.
When people refer to skeletal muscle, they are usually referring to skeletal muscle which is involved in our bodies' movement. However, keep in mind that Lyme disease may also involve the heart muscle and smooth muscle (muscle of the gastrointestinal tract).
The peripheral nerve, nerve-muscle junction, and muscle are collectively referred to as the peripheral nervous system.
With this brief overview, we will now look at some ways that Lyme disease may involve the nervous system. Each condition will be categorized according to the area of the nervous system predominantly affected (which, in itself, is a gross oversimplification, since usually more than one area is affected at a time.)
Brain:
Neuroborreliosis may affect the brain in a number of ways, including:
Aseptic meningitis:
Usually manifested by headache, neck stiffness, fever and disorientation or confusion. It is often mild and may not be sufficient to result in the patient seeking medical attention This may last for hours, days or months, but typically occurs in the initial stages.
Seizures:
Often characterized by abrupt transient loss of consciousness, twitching and jerking. Respiratory distress may occur in a percentage of patients. EEGs may be done to assist in the diagnosis, but findings are not specific to Lyme disease.
Encephalopathy:
Characterized by more chronic cognitive changes, which may involve impaired speech (both receptive and expressive), disorientation, impaired memory, irritability and decreased level of awareness to one's environment. There may be a number of other neuropsychiatric changes, detailed well by Drs. Fallon, et al. Patients with chronic Lyme disease may initially be misdiagnosed with a primary psychiatric disorder. Children with neuroborreliosis may present with developmental delay or, later, with school failure or symptoms of attention deficit disorder, thus being mislabeled as having attention deficit hyperactivity disorder. Whereas ADHD as a primary diagnosis is much more common, neuroborreliosis needs to be included as a possibility, particularly in the child who is exhibiting other possible symptoms of Lyme disease.
Increased intracranial pressure:
Reported in several children with Lyme disease, this would typically present with headaches, double vision and, occasionally, vomiting. In my view, this has been erroneously reported as a "pseudotumor cerebri-like" syndrome. True pseudotumor cerebri is defined by elevated intracranial pressure after the exclusion of all potential causes, including chronic infection. Thus, I think that this title is not accurate and may be misleading.
Extrapyramidal system:
This may be involved in Lyme disease, with symptoms ranging from muscle jerks, rigidity, tremors, exaggerated sleep jerks (myoclonus), tics and cramps.
Cerebellum:
Possibly involved in Lyme disease as manifested by ataxia, a medical term meaning poorly coordinated gait, often accompanied by frequent falling. Ataxia is a symptom, not a diagnosis, and can occur from impairment in different areas of the nervous system
Brainstem:
It can be affected by Lyme disease due to cranial nerve palsies. Cranial nerve involvement has been reported in virtually all of the cranial nerves. Vertigo and dizziness/dysequilibrium from both CNS and PNS dysfunction have been reported with Lyme disease.
Spinal cord:
Transverse myelitis:
An acute disorder of the spinal cord involving area(s) of inflammation or infection that causes motor or sensory malfunction, possibly leading to permanent impairments. As such, it may be due to a variety of possible causes, including multiple sclerosis, viruses or Lyme disease, all of which merit careful investigation.
Peripheral Nerve:
Peripheral neuropathies:
These have been reported, although they are said to be less common in children. They may be sensory (involving abnormal or diminished sensation), which may involve pain, tightness, numbness and tingling or other unusual sensations. Motor neuropathies typically involve weakness and reduced muscle strength and/or bulk in the affected area. Often peripheral neuropathies are mixed motor and sensory.
Radiculoneuropathies:
Involve irritation at the level of the nerve root, where the peripheral nerve joins the spinal cord. Typically, there is pain or discomfort near the spine. Both radiculoneuropathies and peripheral neuropathies may be further defined by eloctromyography and nerve conduction studies (EMG/NCVs), the findings of which are not specific to, or diagnostic of, Lyme disease.
Neuromuscular Junction:
Myasthenia Gravis-like syndrome:
Rarely reported in children, it involves a decrement in muscle power with sustained muscle contraction. This must be confirmed by EMG/NCV.
Muscle:
Myositis:
This is common among patients with both early and late chronic Lyme disease. Muscle symptoms include muscle tenderness, stiffness, cramping and muscle swelling.
In summary, Lyme disease may affect virtually any area of the nervous system and lead to a variety of manifestations, either in isolation or in combination. In addition, as more appropriately reviewed elsewhere, Lyme disease is foremost a clinical diagnosis, with marked difficulties in establishing confirmatory laboratory tests. In addition, concomitant infections may exist, which often need to be addressed. Furthermore, there exists ongoing controversy regarding the duration and nature of therapy, although it can be stated unequivocally that therapy must be individualized.
Lyme disease in children may affect the nervous system in virtually every way that it can in adults, plus it has the added potential for detrimental effects on the developing brain in particular. Pediatricians and pediatric subspecialists face the added challenge of the developmental limitations involved in conveying symptoms from patient to physician.
It should always be borne in mind that Lyme disease is treatable and merits aggressive therapy in order to avoid potentially permanent devastating neurologic impairment.
Suggested Reading:
Belman AL, Coyle PK, Roque C, et al: MRI Findings in Children Infected by Borrelia burgdorferi. Pediatric Neurology 8:428-31.
Belman AL, Iyer M, Coyle PK, et al: Neurologic Manifestations in children with North America Lyme Disease. Neurology 43:2609-2614.
Demaerel P, Wilms G., Casteels K, et al: Childhood neuroborreliosis: clinicoradiological correlation. Paediatric Neuroradiology 37:578-581.
Fallon BA, Nields JA: Lyme Disease: A Neuropsychiatric Illness. Am J Psychiatry 151:1571-1583.
Lawrence C, Lipton RB, Lowry FD and Coyle PK: Seronegative Chronic Relapsing Neuroborreliosis. European Neurology 35: 113-117.
Lesser RL, Kornmehl EW, Pachner AR, et al: Neuro-Opthalmologic Manifestations of Lyme Disease. Ophthalmology 97:699-706.
Pachner AR and Steere AC: The triad of neurologic manifestations of Lyme disease: Meningitis, cranial neuritis, and radiculoneuritis. Neurology 35: 47-53.
Pachner AR: Borrellia burgdorferi in the Nervous System: The New "Great Imitator”. Annals of the New York Academy of Sciences 539: 56-64.
Reik L, Jr.: Lyme Disease. In Scheld WM, Whitley, Durack DT, eds: Infections of the Nervous System, New York, 1996, Raven Press.
Zaidman GW: The Ocular Manifestations of Lyme Disease. International Ophthalmology Clinics 33: 9-22