Difference between revisions of "Key-Gaskell Syndrome"

Revision as of 15:26, 30 July 2010

Introduction

Autonomic polyganglioneuropathy in cats
Abnormal function of the sympathetic and parasympathetic system.
Whole autonomic system involved – affected animals usually die.
- Similar to grass sickness in horses.

Clinical

Cats show:
- Megaoesophagus
- Dilated pupils
- Whole gut is involved (very little peristalsis)
- Constipation.

Generalised autonomic effects:
- Reduced salivation
- Reduced lachrymation
- Bradycardia
- Constipation
- Pupillary dilatation

Pathology

Histologically there is marked reduction in the number of neurones in all autonomic ganglia in the ventral horn of all levels of spinal cord accompanied by proliferation of non-neuronal cells.
Similar changes in brain stem nuclei of cranial nerves.

Pathogenesis

Acquired disease - outbreaks occurred in the past, now only occasionally seen but seems to be getting more common again.
Possibly toxic cause.
Possibly in dry food or in vaccine?
Agent not really known, but produces general damage to autonomic nervous system.

Feline dysautonomia, or Key-Gaskell Syndrome

Histological section of degenerate neuron in feline dysautonomia(Courtesy of Susan Rhind)

Occurs mostly in the UK and continental Europe.
Is also of unknown aetiology. Suggested causative factors include:
- Environmental toxins
- Infectious agents
- Botulinum toxins .
Clinical signs:
- Anorexia
- Depression
- Bradycardia
- Decreased lacrimation,
- Altered pupillary dilataion,
- Megaoesophagus
- Constipation.
Degenerative lesions of autonomic nerve ganglia can be seen.
Also occurs in the oesophagus.

Also known as Feline Key-Gaskell Syndrome and Feline Autonomic Polygangliopathy.

Part of a syndrome of generalised autonomic neuropathy. It has been observed throughout Western Europe and The United States.

Signalment

Historically reported most frequently in cats but now also in dogs
Usually seen in younger dogs
No sex predisposition
In a recent study of 65 dogs confirmed as having dysautonomia those raised and housed in rural environments appeared to be at greater risk (56/65 dogs) for dysautonomia than dogs from the city
Labrador Retrievers may have a breed predisposition

Description

Degenerative lesions of the autonomic ganglia, spinal cord intermediate grey columns and sympathetic axons
Aetiology still largely idiopathic

Diagnosis

Clinical Signs

Those of a generalised autonomic dysfuntion of the gastrointestinal and urinary tracts. Those associated with the oesophagus include:

Regurgitation
Megaoesophagus
Oesophageal hypotmotility

The most frequent clinical signs associated with the syndrome are depression, anorexia, constipation and regurgitation or vomiting. Incontinence (faecal and urinary) has been observed less frequently.

Physical Examination

Findings associated with the GI system include:

Dry mucous membranes
Intestinal distension

Radiography

Plain Radiography

Oesophageal dilatation may be observed.

Contrast Radiography

Oesophageal hypomotility may be evident on barium contrast study.

Histological Findings

Chromatolytic degeneration in autonomic ganglia, spinal cord intermediate grey columns and some sympathetic axons.

Pharmalogical Testing

Topical ocular administration of dilute pilocarpine - miosis implies a postive result. However, not all respond. Response is dependent on damage to the postganglionic parasympathetic neuron causing supersensitivity of the iris muscle
IV or SC administration of atropine (a parasympatholytic) - lack of increase in heart rate implies a positive result
ID administration of histamine - the wheal and flare response may be dampened in those with dysautonomia

Differential Diagnosis

There are few differentials on presentation of the many manifestations of the disease. However, early in the course of disease other causes of megaoesophagus need to be considered.

Treatment

Supportive

Including elevated feeding, gastrostomy tube feedings or total paranteral nutrition.

Parasympathomimetic Drugs

Some dogs may show minor improvement on initiation of for example, bethanechol, metoclopramide.

Prognosis

Guarded to poor. Recovery rates in the cat are reported as 20-40%, however this may take 2-12 months. In the dog recovery rates are lower. Despite recovery many are also left with residual impairment including intermittent regurgitation.

References

Hall J.H, Wimpson J. W. and Williams D.A, (2005), Disorders of the Pharynx and Oesophagus, in BSAVA Manual of Canine and Feline Gastroenterology, 2nd Edition, British Small Animal Association, Gloucester, pp 142-143
Harkin K.R, Andrews G.A, Nietfeld J.C, (2002), Dysautonomia in dogs: 65 cases (1993–2000) J Am Vet Med Assoc, Mar 1, 220(5): pp. 633-9

@@ Line 1: / Line 1: @@
+{{dog}}
+{{cat}}
+==Introduction==
+*Autonomic polyganglioneuropathy in cats
+*Abnormal function of the sympathetic and parasympathetic system.
+*Whole autonomic system involved – affected animals usually die.
+**Similar to [[Grass Sickness|grass sickness]] in horses.
-Also known as: '''''Autonomic Polyganglioneuropathy — Feline Dysautonomia
+=====Clinical=====
+*Cats show:
+**[[Megaoesophagus]]
+**Dilated pupils
+**Whole gut is involved (very little peristalsis)
+**Constipation.
-==Introduction==
+*Generalised autonomic effects:
-Key-Gaskell Syndrome refers to the clinical signs observed in cats with abnormal function of the sympathetic and parasympathetic nervous systems. It is similar to [[Grass Sickness|grass sickness]] in horses and, like this disease, it is often fatal.
+**Reduced salivation
+**Reduced lachrymation
+**Bradycardia
+**Constipation
+**Pupillary dilatation
+=====Pathology=====
+*Histologically there is marked reduction in the number of neurones in all autonomic ganglia in the ventral horn of all levels of spinal cord accompanied by proliferation of non-neuronal cells.
+*Similar changes in brain stem nuclei of cranial nerves.
+=====Pathogenesis=====
+*Acquired disease - outbreaks occurred in the past, now only occasionally seen but seems to be getting more common again.
+*Possibly toxic cause.
+*Possibly in dry food or in vaccine?
+*Agent not really known, but produces general damage to autonomic nervous system.
+=====Feline dysautonomia, or Key-Gaskell Syndrome=====
+[[Image:Ba 250 07.jpg|thumb|right|Histological section of degenerate neuron in feline dysautonomia(Courtesy of Susan Rhind)]]
+* Occurs mostly in the UK and continental Europe.
+* Is also of unknown aetiology. Suggested causative factors include:
+** Environmental toxins
+** Infectious agents
+** Botulinum toxins .
+* Clinical signs:
+** Anorexia
+** Depression
+** Bradycardia
+** Decreased lacrimation,
+** Altered pupillary dilataion,
+** [[Megaoesophagus]]
+** Constipation.
+* Degenerative lesions of autonomic nerve ganglia can be seen.
+* Also occurs in the [[Key-Gaskell Syndrome|oesophagus]].
-The syndrome has occurred as outbreaks<ref>Cave TA, Knottenbelt C, Mellor DJ, Nunn F, Nart P, Reid SW '''Outbreak of dysautonomia (Key-Gaskell syndrome) in a closed colony of pet cats.''' ''Vet Rec. 2003 Sep 27;153(13):387-92.''</ref> in the past in the UK, continental Europe and occasionally in the USA. It was first described by Key and Gaskell as a 'puzzling syndrome' causing pupillary dilatation in cats at the start of a major outbreak in the UK in 1982<ref>Key TJ, Gaskell CJ. '''Puzzling syndrome in cats associated with pupillary dilatation.''' ''Vet Rec. 1982 Feb 13;110(7):160.''</ref>. It is currently described only sporadically but recent reports suggest that the incidence of the disease may be increasing again.
+Also known as Feline Key-Gaskell Syndrome and Feline Autonomic Polygangliopathy.
-The cause of the dysautonomia is not known but numerous factors have been implicated and it is generally thought to occur after exposure to a toxin, possibly in dry food or vaccines [?reference]. As with grass sickness, it has also been suggested that toxins produced by ''[[Clostridium botulinum]]'' may be involved in the pathogenesis of the disease and a recent study showed that cats with the disease developed significantly higher titres of IgA antibody to botulinum toxins C and D than healthy controls<ref>Nunn F, Cave TA, Knottenbelt C, Poxton IR. '''Association between Key-Gaskell syndrome and infection by Clostridium botulinum type C/D.''' ''Vet Rec. 2004 Jul 24;155(4):111-5.''</ref>.  Whatever the cause, degenerative lesions develop in the autonomic ganglia, intermedio-lateral columns of spinal grey matter and in the axons of the sympathetic neurones.
+Part of a syndrome of generalised autonomic neuropathy. It has been observed throughout Western Europe and The United States.
 ==Signalment==
-Historically, Key-Gaskell syndrome was reported most frequently in cats but the disease has now been shown to occur in dogs<ref>Schulze C, Schanen H, Pohlenz J. '''Canine dysautonomia resembling the Key-Gaskell syndrome in Germany.''' ''Vet Rec. 1997 Nov 8;141(19):496-7''</ref><ref>Wise LA, Lappin MR. '''A syndrome resembling feline dysautonomia (Key-Gaskell syndrome) in a dog.''' ''J Am Vet Med Assoc. 1991 Jun 15;198(12):2103-6.''</ref><ref>Rochlitz I, Bennett AM. '''Key-Gaskell syndrome in a bitch.''' ''Vet Rec. 1983 Jun 25;112(26):614-5. ''</ref>, particularly younger animals. There is no apparent sex predisposition but the Labrador Retriever breed may be predisposed to the development of dysautonomia.
+* Historically reported  most frequently in cats but now also in dogs
+* Usually seen in younger dogs
+* No sex predisposition
+* In a recent study of 65 dogs confirmed as having dysautonomia those raised and housed in rural environments appeared to be at greater risk (56/65 dogs) for dysautonomia than dogs from the city
+* Labrador Retrievers may have a breed predisposition
-In a recent study of 65 dogs confirmed as having dysautonomia, those raised and housed in rural environments appeared to be at greater risk (56/65 dogs) for dysautonomia than dogs from urban environments<ref>Harkin KR, Andrews GA, Nietfeld JC. '''Dysautonomia in dogs: 65 cases (1993-2000).''' ''J Am Vet Med Assoc. 2002 Mar 1;220(5):633-9.''</ref>.
+==Description==
+* Degenerative lesions of the autonomic ganglia, spinal cord intermediate grey columns and sympathetic axons
+* Aetiology still largely idiopathic
 ==Diagnosis==
 ===Clinical Signs===
-The sympathetic and parasympathetic nervous systems are involved in the regulation of multiple organ systems, particularly the gastro-intestinal tract and the secretory glands. Common clinical signs therefore include:
+Those of a generalised autonomic dysfuntion of the gastrointestinal and urinary tracts. Those associated with the oesophagus include:
-*'''Anorexia''' and '''constipation''' due to intestinal ileus.
+* Regurgitation
-*'''Abdominal distension''' may occur as a result of generalised paralytic ileus.
+* Megaoesophagus
-*'''[[Megaoesophagus]]''' due to failure of oesophageal motility. This may cause regurgitation and secondary aspiration pneumonia.
+* Oesophageal hypotmotility
-*'''Depression'''
-*'''Bradycardia'''
-*Decreased '''lacrimation''' and '''salivation''' due to reduced tone in the parasympathetic nerves that stimulate secretion. The xerostomia caused by reduced production of saliva may be apparent as dry mucous membranes on clinical examination.
-*'''Pupillary dilatation''' due to reduced tone of the constrictor muscle of the iris, usually controlled by the parasympathetic fibres of the short ciliary nerves.
 The most frequent clinical signs associated with the syndrome are depression, anorexia, constipation and regurgitation or vomiting. Incontinence (faecal and urinary) has been observed less frequently.
-===Diagnostic Imaging===
+===Physical Examination===
-[[Megaoesophagus|Oesophageal dilatation]] may be observed on '''plain radiographs of the chest'''. A 'trachea stripe sign' may also be visible due to the compression of the tissue between the oesophagus and trachea.
+Findings associated with the GI system include:
+* Dry mucous membranes
+* Intestinal distension
-Oesophageal hypomotility may be evident with barium contrast study or using fluoroscopy to observe the dynamic passage of food boluses into the stomach.
+===Radiography===
+====Plain Radiography====
+Oesophageal dilatation may be observed.
+====Contrast Radiography====
+Oesophageal hypomotility may be evident on barium contrast study.
-===Pharmalogical Tests===
+===Histological Findings===
-Various provocative tests can be used to assess the autonomic nervous systems of animals with suspected Key-Gaskell syndrome:
+Chromatolytic degeneration in autonomic ganglia, spinal cord intermediate grey columns and some sympathetic axons.
-*Topical ocular administration of dilute pilocarpine should result in miosis, which implies a positive result. However, not all animals respond and the response is dependent on the degree of damage to the postganglionic parasympathetic neuron causing (denervation) supersensitivity of the iris muscle.
-*Intra-venous or subcutaneous administration of atropine (a parasympatholytic) should result in an increase in the heart rate. A failure to respond implies a positive result.
-*Intra-dermal administration of histamine should result in a classical wheal and flare response but this may be dampened in those animals with dysautonomia. An absence of the wheal and flare response is therefore a positive result.
-=====Pathology=====
+===Pharmalogical Testing===
-[[Image:Ba 250 07.jpg|thumb|Histological section of a degenerate neuron from a cat with Key-Gaskell Syndrome<br><small>Copyright Susan Rhind 2007 RVC]]</small>
+* Topical ocular administration of dilute pilocarpine - miosis implies a postive result. However, not all respond. Response is dependent on damage to the postganglionic parasympathetic neuron causing supersensitivity of the iris muscle
-*Histologically there is marked reduction in the number of neurones in all autonomic ganglia in the ventral horn of all levels of spinal cord accompanied by proliferation of non-neuronal cells.  Similar changes are found in the brainstem nuclei of the cranial nerves and features of chromatolytic degeneration may be apparent in the ganglia, spinal cord and sympathetic axons.
+* IV or SC administration of atropine (a parasympatholytic) - lack of increase in heart rate implies a positive result
+* ID administration of histamine - the wheal and flare response may be dampened in those with dysautonomia
 ==Differential Diagnosis==
-There are few differential diagnoses for this clinical presentation but, early in the course of disease, other causes of [[Megaoesophagus|megaoesophagus]] should be considered.
+There are few differentials on presentation of the many manifestations of the disease. However, early in the course of disease other causes of megaoesophagus need to be considered.
 ==Treatment==
-Treatment may be attempted with parasympathomimteic drugs but is largely supportive.
 ===Supportive===
-Food should be provided from an elevated bowl or via a gastrostomy tube which can be left in place for several weeks if necessary. Total parenteral nutrition may be considered but this cannot be used as a long term option for nutrition and it is associated with many adverse effects.
+Including elevated feeding, gastrostomy tube feedings or total paranteral nutrition.
+===Parasympathomimetic Drugs===
+Some dogs may show minor improvement on initiation of for example, bethanechol, metoclopramide.
-===Parasympathomimetic Drugs===
-Some dogs may show minor improvement on initiation of therapy with '''bethanechol''' or '''metoclopramide'''.
 ==Prognosis==
-The prognosis is guarded or poor. Recovery rates in the cat are reported as 20-40% but it may take 2-12 months for the patient to recover fully. In the dog, recovery rates are lower. Even after making an apparent recovery, many animals are left with residual neurological deficits including intermittent regurgitation.
+Guarded to poor. Recovery rates in the cat are reported as 20-40%, however this may take 2-12 months. In the dog recovery rates are lower. Despite recovery many are also left with residual impairment including intermittent regurgitation.
-{{Learning
-|Vetstream = [https://www.vetstream.com/canis/Content/Disease/dis60161.asp, Canine dysautonomia]<br>[https://www.vetstream.com/felis/Content/Disease/dis60161.asp, Feline dysautonomia]
-|literature search = [http://www.cabdirect.org/search.html?q=%28title%3A%28%22Key+Gaskell%22%29+OR+title%3A%28dysatonomia%29+OR+title%3A%28%22Autonomic+Polyganglioneuropathy%22%29%29+AND+%28od%3A%28cats%29+OR+od%3A%28dogs%29%29 Key-Gaskell Syndrome in cats and dogs publications]
-}}
 ==References==
-<references/>
 * Hall J.H, Wimpson J. W. and Williams D.A, (2005), Disorders of the Pharynx and Oesophagus, in BSAVA Manual of Canine and Feline Gastroenterology, 2nd Edition, British Small Animal Association, Gloucester, pp 142-143
 * Harkin K.R, Andrews G.A, Nietfeld J.C, (2002), Dysautonomia in dogs: 65 cases (1993–2000) J Am Vet Med Assoc, Mar 1, 220(5): pp. 633-9
-{{review}}
-==Webinars==
+[[Category:Oesophagus_-_Pathology]]
-<rss max="10" highlight="none">https://www.thewebinarvet.com/neurology/webinars/feed</rss>
+[[Category:To_Do_-_James]]
-[[Category:Oesophagus_-_Pathology]]
+[[Category:Cat]]
-[[Category:Intestinal Diseases - Cat]][[Category:Neurological Diseases - Cat]][[Category:Oesophageal Diseases - Cat]]
-[[Category:Intestinal Diseases - Dog]][[Category:Neurological Diseases - Dog]][[Category:Oesophageal Diseases - Dog]]
 [[Category:Intestine_-_Functional_Obstruction]]
-[[Category:Peripheral Nervous System - Pathology]]
-[[Category:Expert Review - Small Animal]]
+[[Category:To_Do_-_James]]