MRI Has Limited Diagnostic Value in Early Parkinsonism

SEATTLE — Magnetic resonance imaging performed in the first year or two of parkinsonism seldom yields information useful for establishing the diagnosis.

The final diagnosis in patients with parkinsonism may remain uncertain for years and has historically relied on clinical evaluation and follow-up, lead author Dr. Marie-Josée Langlois said at a poster presentation at the annual meeting of the American Academy of Neurology.

Current guidelines do not specify a clear role for MRI in this setting.

Dr. Langlois and her coinvestigator, Dr. Michel Panisset, both of the University of Montreal, reviewed the charts of consecutive patients with parkinsonism who were evaluated at their institution between 1992 and 2003 and had at least 5 years of follow-up.

Of the 114 patients studied, 25 (22%) had an MRI in the year before or after the initial consultation for parkinsonism. The imaging took place a mean of 1.7 years after the parkinsonism diagnosis.

“Atypical clinical findings and a younger age were the main reasons for doing an MRI,” Dr. Langlois reported. All but two of the imaged patients had findings such as an early onset of falls or a poor response to levodopa, or were aged 50 years or younger.

“We did not find many specific MRI changes,” she said. Of the 25 patients who underwent this imaging, 19 (76%) had normal results, and 6 (24%) had basal ganglia abnormalities.

In the latter group, the abnormalities had a vascular etiology in four patients. Two patients had the same final diagnosis after a mean 6-year follow-up as their initial diagnosis (Parkinson's disease and progressive supranuclear palsy), while two had a change in diagnosis (from focal signs to Parkinson's disease, and from Wilson's disease to Parkinson's disease).

The other two patients with basal ganglia abnormalities on MRI had changes consistent with multiple system atrophy, which was already suspected clinically. In both cases, this initial diagnosis remained unchanged with follow-up.

Overall, in the MRI group, Parkinson's disease (versus atypical or secondary parkinsonism) was the initial diagnosis in 24% of patients and the final diagnosis in 56%. This pattern differed significantly from that in the no-MRI group, which had a mean follow-up of 7 years: Parkinson's disease was the initial diagnosis in 63% of those patients, and the final diagnosis in 76%.

“MRI was not that useful in establishing the initial diagnosis or in changing the diagnosis” in this population with parkinsonism, Dr. Langlois commented.

MRI appears to serve mainly as confirmation of a clinically suspected diagnosis of Parkinson's disease when the results are normal, she noted. “But it may in some cases confirm a clinical diagnosis of atypical parkinsonism, for example, or, if there is a clinical suspicion of a vascular cause, confirm it.”

Other studies that have found higher rates of abnormalities on MRI were conducted in patients who had had parkinsonism for 3.5-5 years, she noted, “so it was not that surprising that with a delay of about 1 year, there is not much change in the MRI.”

However, she added, high-field MRI with fine slices through the basal ganglia and brainstem might reveal changes at such early time points, a possibility that should be explored in a prospective trial.

Dr. Langlois reported that she had no conflicts of interest in relation to the study.

'Atypical clinical findings and a younger age were the main reasons for doing an MRI.' DR. LANGLOIS

SEATTLE — Magnetic resonance imaging performed in the first year or two of parkinsonism seldom yields information useful for establishing the diagnosis.

The final diagnosis in patients with parkinsonism may remain uncertain for years and has historically relied on clinical evaluation and follow-up, lead author Dr. Marie-Josée Langlois said at a poster presentation at the annual meeting of the American Academy of Neurology.

Current guidelines do not specify a clear role for MRI in this setting.

Dr. Langlois and her coinvestigator, Dr. Michel Panisset, both of the University of Montreal, reviewed the charts of consecutive patients with parkinsonism who were evaluated at their institution between 1992 and 2003 and had at least 5 years of follow-up.

Of the 114 patients studied, 25 (22%) had an MRI in the year before or after the initial consultation for parkinsonism. The imaging took place a mean of 1.7 years after the parkinsonism diagnosis.

“Atypical clinical findings and a younger age were the main reasons for doing an MRI,” Dr. Langlois reported. All but two of the imaged patients had findings such as an early onset of falls or a poor response to levodopa, or were aged 50 years or younger.

“We did not find many specific MRI changes,” she said. Of the 25 patients who underwent this imaging, 19 (76%) had normal results, and 6 (24%) had basal ganglia abnormalities.

In the latter group, the abnormalities had a vascular etiology in four patients. Two patients had the same final diagnosis after a mean 6-year follow-up as their initial diagnosis (Parkinson's disease and progressive supranuclear palsy), while two had a change in diagnosis (from focal signs to Parkinson's disease, and from Wilson's disease to Parkinson's disease).

The other two patients with basal ganglia abnormalities on MRI had changes consistent with multiple system atrophy, which was already suspected clinically. In both cases, this initial diagnosis remained unchanged with follow-up.

Overall, in the MRI group, Parkinson's disease (versus atypical or secondary parkinsonism) was the initial diagnosis in 24% of patients and the final diagnosis in 56%. This pattern differed significantly from that in the no-MRI group, which had a mean follow-up of 7 years: Parkinson's disease was the initial diagnosis in 63% of those patients, and the final diagnosis in 76%.

“MRI was not that useful in establishing the initial diagnosis or in changing the diagnosis” in this population with parkinsonism, Dr. Langlois commented.

MRI appears to serve mainly as confirmation of a clinically suspected diagnosis of Parkinson's disease when the results are normal, she noted. “But it may in some cases confirm a clinical diagnosis of atypical parkinsonism, for example, or, if there is a clinical suspicion of a vascular cause, confirm it.”

Other studies that have found higher rates of abnormalities on MRI were conducted in patients who had had parkinsonism for 3.5-5 years, she noted, “so it was not that surprising that with a delay of about 1 year, there is not much change in the MRI.”

However, she added, high-field MRI with fine slices through the basal ganglia and brainstem might reveal changes at such early time points, a possibility that should be explored in a prospective trial.

Dr. Langlois reported that she had no conflicts of interest in relation to the study.

'Atypical clinical findings and a younger age were the main reasons for doing an MRI.' DR. LANGLOIS

SEATTLE — Magnetic resonance imaging performed in the first year or two of parkinsonism seldom yields information useful for establishing the diagnosis.

The final diagnosis in patients with parkinsonism may remain uncertain for years and has historically relied on clinical evaluation and follow-up, lead author Dr. Marie-Josée Langlois said at a poster presentation at the annual meeting of the American Academy of Neurology.

Current guidelines do not specify a clear role for MRI in this setting.

Dr. Langlois and her coinvestigator, Dr. Michel Panisset, both of the University of Montreal, reviewed the charts of consecutive patients with parkinsonism who were evaluated at their institution between 1992 and 2003 and had at least 5 years of follow-up.

Of the 114 patients studied, 25 (22%) had an MRI in the year before or after the initial consultation for parkinsonism. The imaging took place a mean of 1.7 years after the parkinsonism diagnosis.

“Atypical clinical findings and a younger age were the main reasons for doing an MRI,” Dr. Langlois reported. All but two of the imaged patients had findings such as an early onset of falls or a poor response to levodopa, or were aged 50 years or younger.

“We did not find many specific MRI changes,” she said. Of the 25 patients who underwent this imaging, 19 (76%) had normal results, and 6 (24%) had basal ganglia abnormalities.

In the latter group, the abnormalities had a vascular etiology in four patients. Two patients had the same final diagnosis after a mean 6-year follow-up as their initial diagnosis (Parkinson's disease and progressive supranuclear palsy), while two had a change in diagnosis (from focal signs to Parkinson's disease, and from Wilson's disease to Parkinson's disease).

The other two patients with basal ganglia abnormalities on MRI had changes consistent with multiple system atrophy, which was already suspected clinically. In both cases, this initial diagnosis remained unchanged with follow-up.

Overall, in the MRI group, Parkinson's disease (versus atypical or secondary parkinsonism) was the initial diagnosis in 24% of patients and the final diagnosis in 56%. This pattern differed significantly from that in the no-MRI group, which had a mean follow-up of 7 years: Parkinson's disease was the initial diagnosis in 63% of those patients, and the final diagnosis in 76%.

“MRI was not that useful in establishing the initial diagnosis or in changing the diagnosis” in this population with parkinsonism, Dr. Langlois commented.

MRI appears to serve mainly as confirmation of a clinically suspected diagnosis of Parkinson's disease when the results are normal, she noted. “But it may in some cases confirm a clinical diagnosis of atypical parkinsonism, for example, or, if there is a clinical suspicion of a vascular cause, confirm it.”

Other studies that have found higher rates of abnormalities on MRI were conducted in patients who had had parkinsonism for 3.5-5 years, she noted, “so it was not that surprising that with a delay of about 1 year, there is not much change in the MRI.”

However, she added, high-field MRI with fine slices through the basal ganglia and brainstem might reveal changes at such early time points, a possibility that should be explored in a prospective trial.

Dr. Langlois reported that she had no conflicts of interest in relation to the study.

'Atypical clinical findings and a younger age were the main reasons for doing an MRI.' DR. LANGLOIS