Tremor pathophysiology: Difference between revisions

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==Pathophysiology==
==Pathophysiology==
===Physiology===
===Physiology===
The normal physiology of tremor is based on the four oscillatory centers:  
The normal physiology of tremor is based on the four oscillatory centers: <ref name="pmid11360255">{{cite journal| author=Deuschl G, Raethjen J, Lindemann M, Krack P| title=The pathophysiology of tremor. | journal=Muscle Nerve | year= 2001 | volume= 24 | issue= 6 | pages= 716-35 | pmid=11360255 | doi=10.1002/mus.1063 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11360255  }} </ref><ref name="pmid8849966">{{cite journal| author=Deuschl G, Krack P, Lauk M, Timmer J| title=Clinical neurophysiology of tremor. | journal=J Clin Neurophysiol | year= 1996 | volume= 13 | issue= 2 | pages= 110-21 | pmid=8849966 | doi=10.1097/00004691-199603000-00002 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8849966  }} </ref><ref name="pmid8849968">{{cite journal| author=Elble RJ| title=Central mechanisms of tremor. | journal=J Clin Neurophysiol | year= 1996 | volume= 13 | issue= 2 | pages= 133-44 | pmid=8849968 | doi=10.1097/00004691-199603000-00004 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=8849968  }} </ref>
*Mechanical oscillations: Occurs in [[limbs]], could be limited to a particular [[joint]]  
 
*[[Reflex]] oscillations: originate in [[muscle spindles]]
*Mechanical oscillations: Occurs in [[limbs]], could be limited to a particular [[joint]]
, central neuronal pacemaker, and the disturbance in feedforward or feedback loops resulting in oscillations.
*[[Reflex]] oscillations: Originates from afferent [[muscle spindles]]
*Central [[neuronal]] [[pacemaker]]: Involves [[thalamus]], [[basal ganglia]], [[inferior olive]].
*[[Cerebellar]] Oscillations: Disturbance in feedforward or feedback loops in [[cerebellum]] resulting in oscillations.


===Pathogenesis===
===Pathogenesis===
*The exact pathogenesis of [disease name] is not completely understood.
OR
*It is understood that [disease name] is the result of / is mediated by / is produced by / is caused by either [hypothesis 1], [hypothesis 2], or [hypothesis 3].
*[Pathogen name] is usually transmitted via the [transmission route] route to the human host.
*Following transmission/ingestion, the [pathogen] uses the [entry site] to invade the [cell name] cell.
*[Disease or malignancy name] arises from [cell name]s, which are [cell type] cells that are normally involved in [function of cells].
*The progression to [disease name] usually involves the [molecular pathway].
*The pathophysiology of [disease/malignancy] depends on the histological subtype.


==Genetics==
*It is understood that tremor is the result of oscillations produced by the above-mentioned mechanisms.
[Disease name] is transmitted in [mode of genetic transmission] pattern.
*The following are some common causes of tremor and the mechanisms from which they originate: <ref name="pmid11360255">{{cite journal| author=Deuschl G, Raethjen J, Lindemann M, Krack P| title=The pathophysiology of tremor. | journal=Muscle Nerve | year= 2001 | volume= 24 | issue= 6 | pages= 716-35 | pmid=11360255 | doi=10.1002/mus.1063 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=11360255  }} </ref>


OR
{| class="wikitable"
|'''Common Causes of Tremor'''||'''Predominant Mechanism'''
|-
|[[Physiological tremor]]||Mechanical and central
|-
|[[Psychogenic tremor]]||Reflex ([[clonus]])
|-
|[[Symptomatic palatal tremor]]||Central (inferior olive)
|-
|[[Essential tremor]]||Central and [[cerebellar]] ([[olivocerebellar]] circuits)
|-
|[[Parkinson's disease]]||Central ([[basal ganglia]])
|-
|Toxic and drug‐induced tremors||Reflex
|}


Genes involved in the pathogenesis of [disease name] include:
==Genetics==
*[Gene1]
*[Gene2]
*[Gene3]
 
OR


The development of [disease name] is the result of multiple genetic mutations such as:
*[[Essential tremor]] is transmitted in an [[autosomal dominant]] pattern. So far, no particular [[genes]] have been identified as the cause. In Linkage study, three susceptible [[loci]] were mapped in families with pure [[monogenic]] [[essential tremor|essential tremor:]] <ref name="pmid23682623">{{cite journal| author=Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Lorenzo-Betancor O, Pastor P, Agúndez JA| title=Update on genetics of essential tremor. | journal=Acta Neurol Scand | year= 2013 | volume= 128 | issue= 6 | pages= 359-71 | pmid=23682623 | doi=10.1111/ane.12148 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23682623  }} </ref>
 
**3q13
*[Mutation 1]
**2p25-p22
*[Mutation 2]
**6p23
*[Mutation 3]
*[[Wilson's disease]] is transmitted in an [[autosomal recessive]] pattern. <ref name="pmid17276780">{{cite journal| author=Ala A, Walker AP, Ashkan K, Dooley JS, Schilsky ML| title=Wilson's disease. | journal=Lancet | year= 2007 | volume= 369 | issue= 9559 | pages= 397-408 | pmid=17276780 | doi=10.1016/S0140-6736(07)60196-2 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=17276780  }} </ref>
**[[Mutation]] in the [[ATP7B]] [[gene]] on [[chromosome]] 13 (13q14.3)


==Associated Conditions==
==Associated Conditions==
Conditions associated with [disease name] include:
Conditions associated with tremor include:


*[Condition 1]
*[[Parkinson's disease]]
*[Condition 2]
*[[Drug-induced parkinsonism]]:[[Neuroleptics]], [[metaclopromide]],[[phenothiazines]]
*[Condition 3]
*[[Wilson's disease]]
*Metabolic disorders: [[Thyrotoxicosis]], [[pheochromocytoma]], [[hypoglycemia]]
*[[Alcohol withdrawal]]
*[[Peripheral Neuropathy]]
*[[Orthostatic]] tremor
*[[Essential tremor]]


==Gross Pathology==
==Gross Pathology==
On gross pathology, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
On [[gross pathology]], [[Parkinson's disease]] has loss of [[dopamine]] [[pigment]] in the [[substantia nigra]].


==Microscopic Pathology==
==Microscopic Pathology==
On microscopic histopathological analysis, [feature1], [feature2], and [feature3] are characteristic findings of [disease name].
On microscopic histopathological analysis, [[Lewy bodies]] and [[Lewy neurites]] are found in neuronal cell bodies and neuronal cell processes, respectively in patients with [[Parkinson's disease]].


==References==
==References==
{{Reflist|2}}
{{Reflist|2}}
 
[[Category:Neurology]]
{{WH}}
[[Category:Primary care]]
{{WS}}
[[Category:Up-to-date]]
[[Category: (name of the system)]]
[[Category:Signs and symptoms]]
[[Category:Medicine]]

Latest revision as of 16:09, 5 March 2021

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Zehra Malik, M.B.B.S[2]

Overview

It is thought that tremor is the result of a combination of different mechanisms that could result in oscillatory/rhythmic movement. These mechanisms are mechanical oscillations, reflex oscillations, central oscillations, and cerebellar oscillation. These mechanisms differ on the basis of their origin.

Pathophysiology

Physiology

The normal physiology of tremor is based on the four oscillatory centers: [1][2][3]

Pathogenesis

  • It is understood that tremor is the result of oscillations produced by the above-mentioned mechanisms.
  • The following are some common causes of tremor and the mechanisms from which they originate: [1]
Common Causes of Tremor Predominant Mechanism
Physiological tremor Mechanical and central
Psychogenic tremor Reflex (clonus)
Symptomatic palatal tremor Central (inferior olive)
Essential tremor Central and cerebellar (olivocerebellar circuits)
Parkinson's disease Central (basal ganglia)
Toxic and drug‐induced tremors Reflex

Genetics

Associated Conditions

Conditions associated with tremor include:

Gross Pathology

On gross pathology, Parkinson's disease has loss of dopamine pigment in the substantia nigra.

Microscopic Pathology

On microscopic histopathological analysis, Lewy bodies and Lewy neurites are found in neuronal cell bodies and neuronal cell processes, respectively in patients with Parkinson's disease.

References

  1. ↑ 1.0 1.1 Deuschl G, Raethjen J, Lindemann M, Krack P (2001). "The pathophysiology of tremor". Muscle Nerve. 24 (6): 716–35. doi:10.1002/mus.1063. PMID 11360255.
  2. ↑ Deuschl G, Krack P, Lauk M, Timmer J (1996). "Clinical neurophysiology of tremor". J Clin Neurophysiol. 13 (2): 110–21. doi:10.1097/00004691-199603000-00002. PMID 8849966.
  3. ↑ Elble RJ (1996). "Central mechanisms of tremor". J Clin Neurophysiol. 13 (2): 133–44. doi:10.1097/00004691-199603000-00004. PMID 8849968.
  4. ↑ Jiménez-Jiménez FJ, Alonso-Navarro H, García-Martín E, Lorenzo-Betancor O, Pastor P, Agúndez JA (2013). "Update on genetics of essential tremor". Acta Neurol Scand. 128 (6): 359–71. doi:10.1111/ane.12148. PMID 23682623.
  5. ↑ Ala A, Walker AP, Ashkan K, Dooley JS, Schilsky ML (2007). "Wilson's disease". Lancet. 369 (9559): 397–408. doi:10.1016/S0140-6736(07)60196-2. PMID 17276780.
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