Abstract
ABSTRACT
Background –Although idiopathic episodic head tremor (IEHT) in dogs is well-known, little is known about structural brain lesions causing structural episodic head tremor (SEHT).
Hypothesis/Objectives – To describe semiology, MRI findings and outcome of dogs with IEHT or SEHT. We hypothesized that structural lesions affecting the middle cranial fossa or mesencephalic aqueduct could lead to SEHT.
Animals – 100 dogs with IEHT (n=71) or SEHT (n=29).
Methods – Retrospective, multi-center, study of dogs with episodic (non-intentional) head tremor and brain MRI between 2004-2022.
Results – Lesions on MRI in SEHT dogs were localized to the middle cranial fossa (15/29), cerebrocortex (3/29), brainstem (2/29), fourth ventricle (1/29) or multifocal (8/29) with thalamus involvement (6/8). Secondary compression of the mesencephalic aqueduct (19/29), third ventricle and/or interthalamic adhesion (14/29) was common. Most common underlying condition in dogs with SEHT was a pituitary mass. Dogs with SEHT were older, had additional neurological signs
and were more likely to be euthanized after diagnosis (p<0.001 for all) compared to IEHT dogs.
There were two SEHT dogs with only tremor. In IEHT dogs, 8/10 owners reported that the tremor decreased or abated over time (range, 106 – 2315 days) without treatment. In SEHT dogs treated for an underlying meningoencephalitis, tremor remission occurred.
Conclusions/clinical importance – Presence of additional neurological signs and older age may indicate an underlying structural cause for episodic (non-intentional) head tremor involving the mesencephalic aqueduct, third ventricle and/or interthalamic adhesion. An intracranial structural abnormality cannot be excluded in dogs with a normal neurological examination.
Background –Although idiopathic episodic head tremor (IEHT) in dogs is well-known, little is known about structural brain lesions causing structural episodic head tremor (SEHT).
Hypothesis/Objectives – To describe semiology, MRI findings and outcome of dogs with IEHT or SEHT. We hypothesized that structural lesions affecting the middle cranial fossa or mesencephalic aqueduct could lead to SEHT.
Animals – 100 dogs with IEHT (n=71) or SEHT (n=29).
Methods – Retrospective, multi-center, study of dogs with episodic (non-intentional) head tremor and brain MRI between 2004-2022.
Results – Lesions on MRI in SEHT dogs were localized to the middle cranial fossa (15/29), cerebrocortex (3/29), brainstem (2/29), fourth ventricle (1/29) or multifocal (8/29) with thalamus involvement (6/8). Secondary compression of the mesencephalic aqueduct (19/29), third ventricle and/or interthalamic adhesion (14/29) was common. Most common underlying condition in dogs with SEHT was a pituitary mass. Dogs with SEHT were older, had additional neurological signs
and were more likely to be euthanized after diagnosis (p<0.001 for all) compared to IEHT dogs.
There were two SEHT dogs with only tremor. In IEHT dogs, 8/10 owners reported that the tremor decreased or abated over time (range, 106 – 2315 days) without treatment. In SEHT dogs treated for an underlying meningoencephalitis, tremor remission occurred.
Conclusions/clinical importance – Presence of additional neurological signs and older age may indicate an underlying structural cause for episodic (non-intentional) head tremor involving the mesencephalic aqueduct, third ventricle and/or interthalamic adhesion. An intracranial structural abnormality cannot be excluded in dogs with a normal neurological examination.
Original language | English |
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Pages (from-to) | 2301-2309 |
Number of pages | 9 |
Journal | Journal of Veterinary Internal Medicine |
Volume | 37 |
Issue number | 6 |
Early online date | 18 Oct 2023 |
DOIs | |
Publication status | Published - Nov 2023 |