Pratica di Shadowing: Ataxia Series: Neuroimaging patterns not to miss in ataxia - Impara a parlare inglese con YouTube
C2
Hello and welcome to the MTS podcast,
202 frasi
Se le frasi sono troppo corte o troppo lunghe, clicca su Edit per modificarle.
1
Hello and welcome to the MTS podcast,
2
the official podcast of the International Parkinson's Movement Disorders of Life.
3
I am Orlando Barsatini, professor of neurology at Federal University of Sao Paulo, Brazil.
4
And I'm here today with Dr. Malco Rossi.
5
Malco is a movement disorder neurologist and planning institution in Buenos Aires, Argentina.
6
And today we are discussing neuroimaging patterns not to miss in ataxia.
7
Malco, thank you for joining us.
8
Hi, Orlando.
9
Thank you for having me.
10
Thank you, Malco.
11
Malco, this is my first question for you.
12
When you first review an MRI for a patient with ataxia,
13
what are the key elements you systematically evaluated in these patients?
14
The first thing I do is evaluate the cerebellum.
15
I assess whether cerebellar atrophy is present,
16
and if so, whether it is global or follows a specific pattern,
17
such as predominant involvement of the vermis or the cerebellar hemispheres.
18
I always examine the cerebellum in the axial, coronal, and sagittal planes.
19
So, vermian atrophy and in particular superior cerebellar vermis involvement can be especially helpful in the diagnostic process.
20
In some patients, cerebellar volume appears normal on conventional imaging,
21
so in these cases, when available,
22
T1 volumetric MRI can help confirm the absence of overt cerebellar atrophy or reveal mild volume loss.
23
This is particularly relevant because not all causes of ataxia show cerebellar atrophy,
24
especially in the early disease stages.
25
So, it is also very important to evaluate the cerebellar peduncles.
26
Atrophy of the superior cerebellar peduncles can point to specific etiologies,
27
and the superior, middle, and inferior peduncles may show T2
28
or flare hyperintensities that can be very informative in certain causes of ataxia.
29
So, when cerebellar atrophy is present,
30
it is often diffuse and nonspecific,
31
which limits the diagnostic value in clinical practice.
32
For this reason, I then systematically assess for additional MRI abnormalities beyond the cerebellum,
33
like brainstem, basal ganglia, corpus gaiosum, and cortical regions.
34
Other than atrophy patterns, I carefully look for associated signal abnormalities,
35
both hyperintensities and hypointensities that may provide important diagnostic clues,
36
as well as any distinctive imaging features that point towards specific etiologies.
37
So, in other words, in patients with ataxia,
38
the MRI evaluation should follow a structured pattern-based approach rather than focusing only on the cerebellar volume.
39
Okay.
40
And also, in everyday clinics,
41
cerebral atrophy in cerebral antacus is often diffuse and no specific.
42
And now some of the most challenging cases are those where cerebral atrophy is minimal and even absent.
43
My question, which cerebral imaging features do you find the most helpful in daily practice or in evaluation of these patients?
44
The cerebral imaging signs that I find particularly helpful in daily clinical practice are the changes in the cerebral peduncles.
45
Cerebellar peduncul hyperintensities are a well-recognized feature of Fragile X-Associated Traumatoxia Syndrome and can also be seen in MSA Type C.
46
Also, superior cerebellar peduncul hyperintensity is present in up to 60% of patients with SCAR27B.
47
This is a frequent cause of late-onset ataxia,
48
either sporadic or familiar, with typical features including onset after age 45,
49
downbeat nystagmus, episodic worsening, and symptom exacerbation with caffeine.
50
Of importance, SCA27B is a treatable cause of ataxia as many patients respond to 4-aminopiridine.
51
So this makes early recognition of this disorder very important.
52
Also, another point is that superior cerebellar vermis atrophy can be helpful,
53
even though this finding can be seen in some common causes of ataxia,
54
such as free text ataxia,
55
phenocerebellar ataxias, and also in alcoholic cerebellar degeneration,
56
it is also a classic feature of ARSACs,
57
particularly when associated with other typical MRI findings of ARSACs,
58
like the bilateral hypo-intense pontine stridions and the enlarged pons.
59
And as you mentioned, Orlando,
60
many causes of ataxia show diffuse and nonspecific cerebellar atrophy,
61
and in some conditions, cerebellar atrophy may be minimal or even absent,
62
particularly in early disease stages.
63
This can occur in Friedreich's ataxia.
64
Also in ataxia with vitamin E deficiency in adult-onset Alexander disease are in several hereditary spastic paraplycheas
65
that combine spastic paraparasis and ataxia.
66
In these cases, cervical spine MRI to assess for spinal cord atrophy can be very helpful.
67
So for this reason, I routinely assess atrophy patterns beyond the cerebellum,
68
including the brainstem and basal ganglia.
69
For example, combined atrophy of the putamen,
70
pons, and middle cerebellar peduncles points to MSA type C,
71
while midbrain atrophy patterns are characteristic of PSP type C.
72
In addition to atrophy, signal abnormalities,
73
including hyperintensities in the brainstem,
74
spinal cord, basal ganglia, corpus gaiosum,
75
inferior o-lifts, or cerebellar white matter,
76
often provide critical diagnostic clues,
77
particularly early in the disease course.
78
A classic example is the hot cross-band sign,
79
which is highly specific for MSA type C,
80
with an about 98 or 99% specificity,
81
but its sensitivity is limited around 45 to 70%.
82
So of importance, this sign is not pathognomonic and has been reported in several other conditions,
83
including many scars, like SCAL34,
84
as well as immune-mediated or panneoplastic,
85
inflammatory, vascular, and infectious causes of ataxia.
86
This overlap reflects shared pathophysiological mechanisms that include the degeneration of pontine neurons
87
and transverse pontocerebellar fibers with relative sparring of the pontine tegmentum and corticospinal tracts.
88
Also valerian degeneration and gliosis has been reported and so given the broad list of differential diagnosis for the hot crossband sign,
89
the presence of a hot crossband sign needs a clinical correlation,
90
taking into account the age at onset,
91
disease progression, predominant clinical features,
92
laboratory findings, and also additional imaging features.
93
But MSA should remain high on the differential diagnosis unless clearly excluded.
94
Very clear, Malco.
95
Malco, signs like the hot cross band or middle cerebral arthropodical hyperintensive are well known,
96
as you already mentioned.
97
But probably the most important question here is how do we use these findings in real world clinical decisions made?
98
Could You fuck a little bit more.
99
Yes, Orlando.
100
I use these MRI signs as clues rather than diagnostic endpoints.
101
Findings such as the hot crossband sign
102
or middle cerebellar peduncle hyperintensities help me narrow the differential diagnosis and give priority to some etiologies,
103
but they should never be analyzed in isolation.
104
In my clinical practice, I try to integrate MRI findings with a phenotype,
105
like age at onset, rate of progression,
106
and the presence of specific clinical manifestations like oculomoto signs,
107
pyramidal signs, or associated movement disorders.
108
I think that some imaging patterns help me guide the next diagnostic step rather than providing a definitive diagnosis on their own.
109
Although some MRI signs are highly specific when present,
110
their sensitivity is often limited,
111
especially in early disease stages,
112
which means that they should always be interpreted in a clinical context.
113
My diagnostic approach starts with a careful analysis and neurological examination,
114
which in many patients with ataxia sometimes provides a very strong diagnostic clue.
115
Based on this initial assessment,
116
I usually have a short list of differential diagnosis,
117
and a brain MRI then helps me refine and narrow that list.
118
The combination of clinical and imaging features guides targeted laboratory testing.
119
For example, measuring alpha-phytoprotein, which is commonly elevated in ataxia telangiectasia,
120
and some forms of ataxia mid-oculumotor apraxia also.
121
And also you can also measure vitamin E levels,
122
which can also be helpful for the diagnostic process.
123
Neuroimaging also directly influences my genetic testing strategy.
124
Depending on the clinical neuroimaging pattern,
125
I may give priority to testing for repeat expansions versus exam sequencing.
126
For instance, superior cerebellar peduncle hyperintensity,
127
when associated with the corresponding phenotype,
128
raises early suspicions for SCA27b,
129
a repeat expansion ataxia, And then a targeted confirmation should be done.
130
Middle cerebellar peduncle hyperintensities in an adult onset ataxia with axiom tremor makes me consider Fratex,
131
another repeat expansion disorder.
132
And also the presence of a hot crossband sign leads me first to think of MSA type C.
133
But I also consider other possibilities,
134
such as SCAR-34 or immune-mediated ataxias,
135
including anti-Homer-3 or anti-Kelch-like protein 11,
136
depending on disease cause and associated clinical features.
137
In short, neuroimaging signs are most powerful when they are integrated with the clinical picture and used to guide a rational,
138
stepwise diagnostic strategy.
139
Thank you.
140
Welcome.
141
For the next question, particularly I like so much this topic,
142
some imaging signs look like animal shapes and they are easy to remember.
143
Can you name a few examples and how do you use these signs in clinical practice without letting them bias your diagnosis?
144
Yes, both neurologists and neuroradiologists can sometimes experience visual pareidolia,
145
which is the tendency to perceive meaningful shapes,
146
often animals or faces, in random or ambiguous visual patterns.
147
I experienced this a few years ago
148
when a resident asked me to evaluate an MRI of a patient with cerebellar ataxia and unilateral cerebellar hyperintensity.
149
At first glance, the lesion immediately reminded me of a shrimp.
150
So the shrimp sign had already been described,
151
and this is a unilateral lesion in the cerebellar white matter outlining the dentate nucleus.
152
This sign is a reliable indicator of progressive multifocal leucencephalopathy in patients with rapidly progressive cerebellar ataxia.
153
And the patient was evaluated and was finally diagnosed with progressive multifocal leucencephalopathy based on disease characteristic and laboratory findings.
154
Other examples of imaging signs
155
that look like animal's shapes include the crab sign described in SCAV-48
156
that is characterized by dentate nucleus T2 hyperintensities and predominant posterolateral cerebellar hemispheric atrophy.
157
Also the cat pole sign showing marked atrophy of the medulla oblongata and cervical spinal cord with a relatively preserved pons.
158
This is a typical adult-onset Alexander disease finding.
159
And the face of the giant panda is classically associated with Wilson's disease,
160
a condition in which ataxia can be present in some patients,
161
but it has also been reported in isoniazid-induced ataxia.
162
In the cerebellar variant of PSP,
163
midbrain atrophy patterns, such as the hummingbird and mouse sign,
164
show very high specificity, although some sensitivity is limited in early stages.
165
Also, even well-known signs like the eye of the tiger,
166
typically linked to PANC2.
167
They have also been reported in SCAD28.
168
So to sum up, recognizable imaging animal patterns can clearly speed up diagnosis,
169
but they should never be interpreted in isolation.
170
Only by integrating MRI findings with clinical futures,
171
demographics, and laboratory data can we confidently identify typical phenotypes of genetic and acquired ataxias.
172
Okay.
173
Thank you, Marcus.
174
Sometimes for me, it's quite difficult to identify these animal shapes on the brain MRI.
175
Here I have my last question.
176
How do you see advanced MRI techniques,
177
nuclear imaging to earlier diagnosis,
178
disease monitoring, and the future clinical trials in ataxia?
179
I think, Orlando,
180
that neuroimaging will increasingly shift from a purely diagnostic tool to quantitative biomarker of disease progression and also treatment response.
181
We are moving beyond visual pattern recognition to measurable and reproducible metrics,
182
and advanced MRI techniques such as volumetry and diffusion imaging or DTI can detect in the research setting very early,
183
even preclinical changes, and allow us to track progression more sensitively than clinical scales alone.
184
Of importance, mild cerebellar and brainstem volume loss has been shown in persons with spinocerrebellar ataxias like SCA1,
185
2, 3, and 6, even before ataxia develops.
186
I think that also nuclear imaging,
187
while still emerging in ataxias,
188
it has the potential to capture the disease biology,
189
such as neuroinflammation or synaptic dysfunction.
190
I think that together these tools will be very important for early diagnosis,
191
patient stratification and outcome measures in future clinical trials.
192
Okay.
193
Thank you, Marco, for sharing these insights and thank you to our listeners to join us.
194
We hope this episode helps you approach ataxia imaging with greater confidence and precision.
195
Thank you.
196
Thank you, Arlasa.
197
The views
198
and opinions expressed by the participants in this podcast do not necessarily reflect those of the International Parkinson
199
and Movement Disorders Society or their affiliated journals,
200
Movement Disorders and Movement Disorders Clinical Practice.
201
Any disclosures of the participants can be found within the episode description located on the MDS website.
202
you
Scarica l'app
Valutazione AI per ogni frase che pronunci
TRENDING
Popolari
Informazioni su questa lezione
In questa lezione, avrai l'opportunità di praticare il tuo inglese ascoltando una discussione approfondita sui modelli di neuroimaging nell'atassia. Attraverso l'analisi di un podcast, potrai migliorare la tua comprensione dell'argomento medico e sviluppare la tua pronuncia e fluidità nella lingua inglese. L'obiettivo è combinare la tua passione per la salute e la medicina con la pratica della lingua, sfruttando il metodo di shadowing per affinare le tue abilità linguistiche.
Vocabolario e frasi chiave
- Atassia - Ataxia
- Neuroimaging - Neuroimaging
- Cerebello - Cerebellum
- Atrofia cerebellare - Cerebellar atrophy
- Peda cerebellari - Cerebellar peduncles
- Ipersensibilità - Hyperintensities
- Volume cerebellare - Cerebellar volume
- Trattabile - Treatable
Consigli per la pratica
Per trarre il massimo vantaggio da questa lezione, ti consigliamo di utilizzare una tecnica di shadowing in inglese. Inizia ascoltando l'audio a un ritmo comodo per te, rendendoti conto della pronuncia e dell'intonazione dei relatori. Una volta che ti senti più sicuro, prova a ripetere le frasi in tempo reale, imitando la loro cadenza e pronuncia. Questo approccio, noto anche come shadow speech, ti aiuterà a migliorare non solo la tua pronuncia, ma anche la tua abilità nel comprendere e utilizzare il lessico medico specifico. Ricorda di riascoltare e ripetere frequentemente, utilizzando il tuo shadow speak per integrare nuovi vocaboli e frasi nel tuo parlato quotidiano. Puoi trovare risorse di shadowing site all'interno di vari portali didattici, che potrebbero offrirti ulteriore supporto nella tua pratica linguistica.
Cos'è la tecnica dello Shadowing?
Shadowing è una tecnica di apprendimento delle lingue supportata da studi scientifici, originariamente sviluppata per la formazione dei traduttori professionisti e resa popolare dal poliglotta Dr. Alexander Arguelles. Il metodo è semplice ma potente: ascolti un audio in inglese di madrelingua e lo ripeti immediatamente ad alta voce — come un'ombra che segue il parlante con un ritardo di solo 1–2 secondi. A differenza dell'ascolto passivo o degli esercizi di grammatica, lo shadowing costringe il tuo cervello e i muscoli della bocca a elaborare e riprodurre simultaneamente i modelli di discorso reale. La ricerca dimostra che migliora significativamente la precisione della pronuncia, l'intonazione, il ritmo, il discorso connesso, la comprensione dell'ascolto e la fluidità del parlato — rendendolo uno dei metodi più efficaci per la preparazione alla prova di speaking dell'IELTS e per la comunicazione reale in inglese.
☕ Offrici un caffè
ShadowingEnglish rimane gratuito al 100% grazie al tuo supporto. I costi del server e IA sono elevati — il tuo caffè ci aiuta ad andare avanti! 🙏